Binder resin containing novel polyhydroxyalkanoate, toner containing the binder resin, and image-forming method and image-forming apparatus which make use of the toner

ABSTRACT

A binder resin which forms a resin powdery product such as a toner for developing electrostatic latent images. The binder resin comprises a biodegradable resin comprising a polyhydroxyalkanoate produced by culturing a microorganism and having as a specific monomer unit a 3-hydroxyalkanoic acid such as 3-hydroxy-5-phenylvaleric acid. This binder resin has very good properties as a binder resin and also has a high safety to human bodies and environment. Also disclosed are a toner for developing electrostatic latent images which contains such a binder resin, and an image-forming method and an image-forming apparatus which make use of the toner.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a binder resin usable in toners for developingelectrostatic latent images, a toner for developing electrostatic latentimages, an image-forming method making use of the toner and animage-forming apparatus making use of the toner. More particularly, itrelates to a binder resin, a toner for developing electrostatic latentimages, an image-forming method and an image-forming apparatus which areused in electrophotography, electrostatic recording and electrostaticprinting performed in copying machines, printers, facsimile machines andso forth, in which a toner image is previously formed on anelectrostatic-latent-image-bearing member (hereinafter simply“image-bearing member”) and is thereafter transferred onto a transfermedium to form an image. Still more particularly, it relates to a binderresin which has a biodegradability and at the same time contributes tosuperior fixing performance (low-temperature fixing performance, fixingtemperature characteristics and anti-offset properties) and blockingresistance, and which has hydrolyzability and biodegradability and canreadily be deinked, where existing deinking systems can be utilized asthey are, also enabling waste disposal with ease; a toner for developingelectrostatic latent images which contains such a binder resin; and animage-forming method and an image-forming apparatus which make use ofthe toner.

2. Related Background Art

A number of methods are conventionally known as methods forelectrophotography. In general, copies are obtained by forming anelectrostatic latent image on an image-bearing member (photosensitivemember) by utilizing a photoconductive material and by various means,subsequently developing the latent image by the use of a toner to form avisible image (toner image), transferring the toner image to a transfermedium such as a paper as occasion calls, and then fixing the tonerimage to the transfer medium by heating and/or pressing. As methods bywhich the electrostatic latent image is formed into a visible image,cascade development, magnetic brush development, pressure developmentand so forth are known in the art. Another method is also known inwhich, using a magnetic toner and a rotary developing sleeve providedwith magnetic poles at the core, the magnetic toner is caused to flyfrom the developing sleeve surface to the photosensitive member surfaceby the aid of an electric field.

As development methods used when electrostatic latent images aredeveloped, available are a two-component development method making useof a two-component type developer comprised of a toner and a carrier anda one-component development method making use of no carrier andcomprised only of a toner.

Now, fine colored particles commonly called a toner are constituted of abinder resin and a colorant as essential components and besidesoptionally a magnetic material and so forth. Here, the binder resinoccupies the greater part of the toner, and hence the physicalproperties of such a binder resin influence toner's physical propertiesgreatly. For example, the binder resin is required to have delicatehardness and thermal melt properties, and a toner obtained bypulverizing a binder resin having a colorant and so forth dispersedtherein followed by classification must show good fluidity withoutproducing any fine powder against a mechanical impact caused byagitation in a developing assembly and also without causingagglomeration of the toner itself. Also, at the time of fixing, thetoner must immediately melt at a low temperature and, when melts, themolten toner must show agglomeration properties. Namely, the controllingof binder resin's physical properties enables control of toner'sphysical properties.

As the binder resin, conventionally used are a styrene-acrylatecopolymer, polyester resin, epoxy resin, olefinic resin and so forth. Inparticular, polyester resin is widely used at present as a resin fortoners for heat-roll fixing, because, e.g., it has advantages such that,when melt, it makes toner additives such as carbon black disperse welland is well wettable to transfer paper.

In recent years, from the viewpoint of environmental conservation, it isalso of worldwide consciousness how resources be recycled, how waste becurtailed, how the safety of waste be improved, and so forth. Such asubject is not exceptional also in the field of electrophotography. Morespecifically, with wide spread of copying machines and printers, thedisposal of fixed toner on paper, waste toner after use, printed paper,copying paper and so forth is increasing year by year. Here,conventional toners are sparingly degradable because they areconstituted of components all of which are stable artificial compounds,and may remain in all environment, e.g., in soil and in water over along period of time. Also, in order to recycle resources, it is animportant subject to regenerate plain paper for its reuse. However,conventional binder resins composed chiefly of styrene resins, it isdifficult to remove them from paper surface (deinking) by alkalihydrolysis. This has come to be one of subjects in the recycling ofplain paper. The safety of waste is also an important subject from thestandpoints of the conservation of global environment and the influenceon human bodies.

Under such circumstances, development is being made on resins which areharmless to human bodies and degradable by the action of microorganisms,i.e., biodegradable resins. For example, it has been reported that manymicroorganisms are capable of producing a biodegradable resinpolyhydroxyalkanoate (hereinafter “PHA” when abbreviated) andaccumulating it in the cell (“Handbook of Biodegradable Plastics”,Biodegradable-Plastic Institute, K.K. N.T.S., pp.178-197, 1995). It isknown that such a PHA can have various composition and structuredepending on the type of microorganisms used for its production, thecomposition of culture medium, the conditions for culturing and soforth. Researches on how to control the composition and structure of thePHA to be produced have hitherto chiefly been made from the viewpoint ofthe improvement in its physical properties. With regard to theapplication of such biodegradable resins, too, they have already givenreasonable actual results especially in the field of materials formedical use. In the field of agriculture, too, the biodegradable resinshave been put into practical use in multifiles, gardening material,sustained-release agricultural chemicals, fertilizers and so forth. Inthe field of leisure industry, too, the biodegradable resins are used infishing lines, fishing articles, golf goods and so forth. Besides, aspackaging materials for daily necessities, they have been put intopractical use in containers or the like of living articles. However,considering their wide application as plastics, under the existingconditions they can not still be said to be satisfactory in respect ofphysical properties. For example, in order to make the PHA utilizable inmuch wider ranges, it is important to study the improvement of physicalproperties more widely. For that end, it is essential to makedevelopment and research on PHAs containing monomer units of variousstructures.

In the field of electrophotography, too, methods in which biodegradableresins are used in binder resins are proposed as methods by which tonerswhich are disposable without causing environmental pollution. Forexample, Japanese Patent Application Laid-Open No. 6-289644 discloses anelectrophotographic toner particularly used for heat-roll fixing, whichis characterized in that at least a binder resin contains a vegetablewax and a biodegradable resin (as exemplified by polyesters produced bymicroorganisms and natural polymeric materials derived from vegetablesor animals), and the vegetable wax is added to the binder resin in anamount of from 5 to 50% by weight. Japanese Patent Application Laid-OpenNo. 8-262796 also discloses an electrophotographic toner containing abinder resin and a colorant, and is characterized in that the binderresin comprises a biodegradable resin (as exemplified by aliphaticpolyester resins) and the colorant comprises a water-insoluble coloringmatter. Also, U.S. Pat. No. 5,004,664 discloses a toner having as itscomposition polyhydroxybutyric acid, polyhydroxyvaleric acid, or acopolymer or blend of these. In these techniques, when buried fordisposal, the binder resins can certainly be degraded in soil becausethey are biodegradable. However, there have been problems on fundamentalfunction as binder resins, such that the toner has a low runningperformance and also is unstably chargeable because of its high moistureabsorption. For example, the PHB is a hard and brittle material havingproperties of a melting point of 180° C., a crystallinity of 50 to 70%,a Young's modulus of 3.5 GPa and a breaking extension of 5%, and isinsufficient in practical use for its use as the binder resin of toner.

A toner composed chiefly of a polylactic acid type aliphatic polyesteris also proposed as having a biodegradability and also being efficientlydegradable in alkali hydrolysis and hence being useful for the recyclingof paper. For example, Japanese Patent Application Laid-Open No.7-120975 also discloses a method of making a lactic-acid homopolymerinto a toner, giving as its typical example a polylactic acid obtainedby ring-opening polymerization.

In the ring-opening polymerization, a method is employed in which thelactic acid is first made into an oligomer by dehydration reaction,which oligomer is then subjected to depolymerization to lead it to acyclic dimer lactide and is further subjected to ring-openingpolymerization. Since such complicate steps are followed, the resultantpolylactic acid comes very highly expensive for its use as a toner resin(a resin for toners).

In addition, since the ring-opening polymerization is cationicring-opening polymerization, it is necessary, e.g., to make unhydrousthe solvent used and to remove any ionic species which may serve as apolymerization terminator, resulting in a poor production efficiency.Moreover, the monomer species that can be used when the polyester isproduced is limited to a cyclic ester, and hence it is not easy tocontrol physical properties required as toner resins. It is alsodifficult to effect copolymerization with various monomers in order tocontrol the balance between degradability and physical properties. Inthis regard, it is sought to provide a degradable polyester that cancontrol its physical properties inexpensively and with ease. Also, whenthe polylactic acid is made into a toner as it is, there are problemsalso on the storage stability and anti-offset properties of the toner.Thus, such a toner has not yet been put into practical use.

Japanese Patent Application Laid-Open No. 9-274335 also discloses atoner for developing electrostatic latent images which is characterizedby containing a polyester resin and a colorant; the former beingobtained by dehydration polycondensation of a composition containinglactic acid and a tri- or more functional oxycarboxylic acid. However,the polyester resin is formed through dehydration polycondensationreaction of an alcohol group of the lactic acid with a carboxylic groupin the oxycarboxylic acid. Hence, it is considered that the resultantresin tends to have a large molecular weight, and therefore has a lowbiodegradability. Also, like the one disclosed in Japanese PatentApplication Laid-Open No. 7-120975, there are problems on the storagestability and anti-offset properties of the toner.

Polycaprolactone, which is a homopolymer of a typical hydroxycarboxylicacid, also has a low melting point and a low glass transition point andhas good compatibility with various resins. It, however, has a meltingpoint of as low as 60° C., and is not suitable as a binder resin whenused alone. Also, the polylactic acid has a high glass transition point(60° C.), and one having crystallizability is a thermoplastic highpolymer having a high melting point (about 180° C.), which, however, hasnot yet been put into practical use as a binder resin as statedpreviously. Moreover, toner resins comprised of the conventionaldegradable polyester resin commonly have so poor a pulverizability thatit is difficult for them to be used as binder resins which occupy 90% oftoners of about 10 μm in particle diameter. Accordingly, taking accountof their practical use as binder resins of toners, it has strongly beendesired to improve their physical properties,

SUMMARY OF THE INVENTION

The present invention is to settle the subjects or problems discussedabove. Accordingly, an object of the present invention is to provide abinder resin which is biodegradable and can more highly contribute tothe conservation of natural environment, and also which enables deinkingwith ease in a conventionally available deinking process making use ofan alkali, to promote the reuse of copying paper having been used, andcan satisfy various performances and properties required as toners,e.g., those concerning carrier-spent, fog, charging stability, runningperformance, storage stability, pulverizability, cost and so forth; atoner for developing electrostatic latent images which comprises such abinder resin; and an image-forming method and an image-forming apparatuswhich make use of the toner.

The present inventors have made extensive studies in order to achievethe above object. As the result, they have discovered that a binderresin comprising a polyhydroxyalkanoate having monomer unit compositionrepresented by the following Formula (1) has very good properties as abinder resin and also has a high safety to human bodies and environment.They have also discovered that remarkable effects can be brought aboutwhen a toner for developing electrostatic latent images which containssuch a binder resin is used and this toner for developing electrostaticlatent images is used in image-forming apparatus having a certaindevelopment system. Thus, they have accomplished the present invention.

More specifically, the binder resin of the present invention ischaracterized by containing a polyhydroxyalkanoate having monomer unitcomposition represented by the following Formula (1):AmB(1−m)  (1)wherein A is at least one selected from monomer units represented by thefollowing Formula (2), B is at least one selected from monomer unitsrepresented by the following Formulas (3) and (4), and m is 0.01 or moreand 1 or less:

wherein n is 0 to 10, k is 3 or 5, and R is any group selected fromgroups represented by the following Formulas (5) to (8):

wherein;

-   -   in Formula (5), R1 is selected from a hydrogen atom (H) and a        fluorine atom (F), and q is selected from integers of 1 to 8;    -   in Formula (6), R2 is selected from a hydrogen atom (H) and a        fluorine atom (F), and r is selected from integers of 1 to 8;    -   in Formula (7), R3 is selected from a hydrogen atom (H) and a        fluorine atom (F), and s is selected from integers of 1 to 8;        and    -   in Formula (8), R4 is selected from a hydrogen atom (H) and a        fluorine atom (F), and t is selected from integers of 1 to 8.

The toner for developing electrostatic latent images according to thepresent invention is also characterized by containing the binder resinconstituted as described above.

The image-forming method according to the present invention is animage-forming method comprising:

-   -   a charging step of applying a voltage to a charging member from        its outside to charge an electrostatic-latent-image-bearing        member electrostatically;    -   a latent-image-forming step of forming an electrostatic latent        image on the electrostatic-latent-image-bearing member thus        charged;    -   a developing step of developing the electrostatic latent image        by the use of a toner for developing electrostatic latent        images, to form a toner image on the        electrostatic-latent-image-bearing member;    -   a transfer step of transferring to a recording medium the toner        image formed on the electrostatic-latent-image-bearing member;        and    -   a fixing step of fixing by heat the toner image held on the        recording medium;    -   wherein the toner for developing electrostatic latent images        described above is used.

In another embodiment of the image-forming method according to thepresent invention, it is an image-forming method comprising:

-   -   a charging step of applying a voltage to a charging member from        its outside to charge an electrostatic-latent-image-bearing        member electrostatically;    -   a latent-image-forming step of forming an electrostatic latent        image on the electrostatic-latent-image-bearing member thus        charged;    -   a developing step of developing the electrostatic latent image        by the use of a toner for developing electrostatic latent        images, to form a toner image on the        electrostatic-latent-image-bearing member;    -   a first transfer step of transferring to an intermediate        transfer member the toner image formed on the        electrostatic-latent-image-bearing member;    -   a second transfer step of transferring to a recording medium the        toner image held on the intermediate transfer member; and    -   a fixing step of fixing by heat the toner image held on the        recording medium;    -   wherein the toner for developing electrostatic latent images        described above is used.

The image-forming apparatus according to the present invention is animage-forming apparatus comprising:

-   -   a charging means for applying a voltage to a charging member        from its outside to charge an electrostatic-latent-image-bearing        member electrostatically;    -   a latent-image-forming means for forming an electrostatic latent        image on the electrostatic-latent-image-bearing member thus        charged;    -   a developing means for developing the electrostatic latent image        by the use of a toner for developing electrostatic latent        images, to form a toner image on the        electrostatic-latent-image-bearing member;    -   a transfer means for transferring to a recording medium the        toner image formed on the electrostatic-latent-image-bearing        member; and    -   a fixing means for fixing by heat the toner image held on the        recording medium;    -   wherein the toner for developing electrostatic latent images        described above is used.

In another embodiment of the image-forming apparatus according to thepresent invention, it is an image-forming apparatus comprising:

-   -   a charging means for applying a voltage to a charging member        from its outside to charge an electrostatic-latent-image-bearing        member electrostatically;    -   a latent-image-forming means for forming an electrostatic latent        image on the electrostatic-latent-image-bearing member thus        charged;    -   a developing means for developing the electrostatic latent image        by the use of a toner for developing electrostatic latent        images, to form a toner image on the        electrostatic-latent-image-bearing member;    -   a first transfer means for transferring to an intermediate        transfer member the toner image formed on the        electrostatic-latent-image-bearing member;    -   a second transfer means for transferring to a recording medium        the toner image held on the intermediate transfer member; and    -   a fixing means for fixing by heat the toner image held on the        recording medium;    -   wherein the toner for developing electrostatic latent images        described above is used.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an image-forming apparatus used inExamples 45 to 72 and Comparative Examples 3 and 4.

FIG. 2 is a sectional view of the main part of a developing assembly fortwo-component developer, used in Examples 45 to 72 and ComparativeExamples 3 and 4.

FIG. 3 is a schematic illustration of an image-forming apparatus havinga toner reuse mechanism, used in Examples 73 to 84 and ComparativeExamples 5 and 6.

FIG. 4 is a sectional view of the main part of a developing assembly forone-component developer, used in Examples 73 to 84 and ComparativeExamples 5 and 6.

FIG. 5 is an exploded, perspective view of the main part of a fixingassembly used in Examples of the present invention.

FIG. 6 is an enlarged sectional view of the main part of a fixingassembly used in Examples of the present invention, which shows how afixing film stands when the fixing assembly is not driven.

FIG. 7 is a diagrammatic illustration of a blow-off charge quantitymeasuring unit with which the charge quantity of toners is measured.

FIG. 8 is a chart showing a 1H-NMR spectrum of a PHA in Example 5.

FIG. 9 is a chart showing a 1H-NMR spectrum of a PHA in Example 8.

FIG. 10 is a chart showing a 13C-NMR spectrum of a PHA in Example 8.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the present invention are described below.

The binder resin according to the present invention contains at leastthe PHA having monomer unit composition represented by Formula (1)expressed above. Also, two or more types of PHAs having differentmonomer unit composition may be used in combination. Still also, thisbinder resin may be a binder resin containing at least one of additionalbiodegradable resins such as polycaprolactone and polylactic acid.

As the polylactic acid, commercially available one, e.g., LACTY (tradename; available from Shimadzu Corporation) may preferably be used, andbesides those obtained by various polymerization processes may be used.

In the case when the additional biodegradable resin is used, theadditional biodegradable resin may preferably be mixed in a proportionof 90% by weight or less based on the total weight of the binder resin,taking account of biodegradability and of physical properties requiredas binder resins.

The PHA may preferably have a number-average molecular weight of 300,000or less because, in such molecular weight, it can have a goodcompatibility with the polycaprolactone or polylactic acid and a moltenpolymer blend which is colorless and transparent is obtainable. If onthe other hand it has a relatively large number-average molecular weightof 500,000 or more, it can not have so good compatibility, and theresultant molten polymer blend may also have not a good hue. Even insuch a case, however, the PHA can be improved in compatibility and thecolorless and transparent, molten polymer blend can be obtained bymixing them under application of a high shear force to lower itsmolecular weight to 300,000 or less.

The binder resin of the present invention may also preferably have anumber-average molecular weight of from 2,000 to 300,000. The binderresin of the present invention may further preferably have a glasstransition point of from 30° C. to 80° C. and a softening point of from60° C. to 170° C. in order for the function as a binder resin to bebrought out.

Here, the PHA used in the present invention has a fundamental skeletonas a biodegradable resin. Hence, like conventional plastic, it can beutilized in the manufacture of various products by melting, and,different from synthetic polymers derived from petroleum, has a strikingproperty that it is readily broken down by microorganisms and taken intothe circulation of substances in the natural world. Accordingly, it doesnot require any disposal by combustion, and is an effective materialalso from the viewpoint of the prevention of air pollution and globalwarming. Thus, it can be utilized as a plastic which enablesenvironmental safeguard.

The PHA is also capable of being readily hydrolyzed in the presence ofalkaline water. Hence, it has an advantage that toners containingcoloring matter such as carbon black can effectively be removed fromcopied paper.

The PHA having monomer unit composition represented by Formula (1),which is preferable as the binder resin used in the toner for developingelectrostatic latent images according to the present invention, isspecifically described below. The PHA used in the present invention is apolyester resin having a 3-hydroxyalkanoate as a monomer unit andcontaining as a substituent at least one of any of substituents selectedfrom phenyl, phenoxyl, cyclohexyl and benzoyl groups. Here, where such acompound is produce by utilizing a microorganism, the polyester resin isan isotactic polymer consisting of only R-configuration. As long as theobject of the present invention is achievable on both aspects ofphysical properties and function, it need not especially be theisotactic polymer. An atactic polymer may also be used. Also, the PHAmay also be obtained by a process of chemical synthesis in which alactone compound is subjected to ring-opening polymerization using anorganometallic catalyst (e.g., an organic catalyst containing aluminum,zinc, tin or the like).

What is important in the present invention is that, in respect of theside-chain structures represented by Formulas (5) to (8), R1 to R4 maybe selected as at least one atom selected from the group consisting of ahydrogen atom and a fluorine atom. Here, in respect of the side-chainstructures represented by Formulas (5) to (8), these may be formed asaromatic rings the R1 to R4 of which have been substituted with fluorineatoms, whereby the resultant compounds can be made to have much lessenvironmental dependence. In the case when any of R1 to R4 issubstituted with a fluorine atom, such a monomer unit containing thefluorine atom may be contained in the polymer in an amount of at least 1mol %. Its proportion may be selected taking account of the desiredenvironmental dependence.

As the position at which R1 to R4 are substituted, it may be ortho-,meta- or para-position, at any positions of which polyhydroxyalkanoateshaving the corresponding monomer units can be gained. Where there is nogreat difference in function characteristics, physical properties and soforth between any isomers, compounds substituted at the meta- orpara-position may preferably be used in view of the yield or thereadiness of being incorporated into the polymer.

Here, when the PHA of the present invention is produced by using amicroorganism, it may contain the above various monomer units, or may beso designed that it may contain a suitable number of units, takingaccount of any necessary function characteristics, physical propertiesand so forth of the polymer. In general, the PHA may contain the monomerunits as far as the above six kinds, where it is expected that theobject of the present invention can sufficiently be achieved. Where anydelicate control of function characteristics and physical properties isintended, the PHA may also be constituted of more kinds of monomerunits.

The PHA in the present invention may preferably have a glass transitionpoint of from 30° C. to 80° C., particularly preferably from 40° C. to80° C., and more preferably from 50° C. to 70° C. If it has a valuelower than 30° C., a poor blocking resistance tends to result. If it hasa value higher than 80° C., a poor fixing performance tends to result.Also, the PHA in the present invention may preferably have a softeningpoint of from 60° C. to 170° C., and particularly preferably from 80° C.to 140° C. If it has a softening point lower than 60° C., a lowering ofanti-offset properties may be seen. If it has a softening point higherthan 170° C., a higher fixing temperature tends to result.

The PHA having these desired physical properties may be obtained byselecting conditions for culturing any microorganism capable ofsynthesizing the PHA in the present invention. For example, itsnumber-average molecular weight may be controlled by controllingculturing time and so forth. Its number-average molecular weight mayalso be controlled by removing low-molecular-weight components by meansof solvent extraction, re-precipitation or the like. Here, the glasstransition point and softening point have correlation with the molecularweight of the PHA. Also, the glass transition point and softening pointmay be controlled by controlling the type and compositional ratio of themonomer units in the PHA.

The PHA in the present invention may preferably have a weight-averagemolecular weight Mw of from 4,000 to 300,000, and may preferably have anumber-average molecular weight Mn of from 2,000 to 150,000, andparticularly preferably from 5,000 to 100,000. If it has an Mn of lessthan 2,000, the PHA may have a greatly low glass transition point,resulting in a poor blocking resistance. If on the other hand it has anMn of more than 150,000, the PHA may come highly viscous at the time ofmelting, resulting in a poor low temperature fixing performance.

Exemplification of PHA and Production of PHA

Biosynthesis as a specific process for obtaining the PHA having monomerunit composition represented by Formula (1) can be effected where amicroorganism capable of producing the polyhydroxyalkanoate containingthe monomer units represented by Formulas (2) to (4), from theircorresponding alkanoic acids is cultured in a culture medium containingthe corresponding alkanoic acids. Culturing methods and so forth aredescribed later.

For example, a microorganism capable of producing a polyhydroxyalkanoatecontaining a 3-hydroxy-5-phenylvaleric acid (3HPV) monomer unitrepresented by the following Formula (9) from 5-phenylvaleric acid (PVA)represented by the following Formula (10) may be cultured to obtain apolyhydroxyalkanoate containing the 3HPV monomer unit.

A microorganism capable of producing a polyhydroxyalkanoate containing a3-hydroxy-5-(4-fluorophenyl)valeric acid (3HFPV) monomer unitrepresented by the following Formula (11) from 5-(4-fluorophenyl)valericacid (FPVA) represented by the following Formula (12) may also becultured to obtain a polyhydroxyalkanoate containing the 3HFPV monomerunit.

A microorganism capable of producing a polyhydroxyalkanoate containing a3-hydroxy-4-phenoxybutyric acid (3HPxB) monomer unit represented by thefollowing Formula (13) from 4-phenoxybutyric acid (PxBA) represented bythe following Formula (14) may also be cultured to obtain apolyhydroxyalkanoate containing the 3HPxB monomer unit.

A microorganism capable of producing a polyhydroxyalkanoate containing a3-hydroxy-5-phenoxyvaleric acid (3HPxV) monomer unit represented by thefollowing Formula (15) from 5-phenoxyvaleric acid (PxVA) represented bythe following Formula (16) may also be cultured to obtain apolyhydroxyalkanoate containing the 3HPxV monomer unit.

A microorganism capable of producing a polyhydroxyalkanoate containing a3-hydroxy-(4-fluorophenoxy)butyric acid (3HFPxB) monomer unitrepresented by the following Formula (17) from4-(4-fluorophenoxy)butyric acid (FPxBA) represented by the followingFormula (18) may also be cultured to obtain a polyhydroxyalkanoatecontaining the 3HFPxB monomer unit.

A microorganism capable of producing a polyhydroxyalkanoate containing a3-hydroxy-4-cyclohexylbutyric acid (3HCHB) monomer unit represented bythe following Formula (19) from 4-cyclohexylbutyric acid (CHBA)represented by the following Formula (20) may also be cultured to obtaina polyhydroxyalkanoate containing the 3HCHB monomer unit.

A microorganism capable of producing a polyhydroxyalkanoate containing a3-hydroxy-4-(4-fluorocyclohexyl)butyric acid (3HFCHB) monomer unitrepresented by the following Formula (21) from4-(4-fluorocyclohexyl)butyric acid (FCHBA) represented by the followingFormula (22) may also be cultured to obtain a polyhydroxyalkanoatecontaining the 3HFCHB monomer unit.

A microorganism capable of producing a polyhydroxyalkanoate containing a3-hydroxy-5-benzoylvaleric acid (3HBzV) monomer unit represented by thefollowing Formula (23) from 5-benzoylvaleric acid (BzVA) represented bythe following Formula (24) may also be cultured to obtain apolyhydroxyalkanoate containing the 3HBzV monomer unit.

A microorganism capable of producing a polyhydroxyalkanoate containing a3-hydroxy-5-(4-fluorobenzoyl)valeric acid (3HFBzV) monomer unitrepresented by the following Formula (25) from5-(4-fluorobenzoyl)valeric acid (FBzVA) represented by the followingFormula (26) may also be cultured to obtain a polyhydroxyalkanoatecontaining the 3HFBzV monomer unit.

A microorganism capable of producing a polyhydroxyalkanoate containing3-hydroxy-5-(4-fluorophenyl)valeric acid (3HFPV) and3-hydroxy-5-(4-fluorophenoxy)valeric acid (3HFPxV) monomer unitsrepresented by the following Formulas (11) and (27), respectively, from5-(4-fluorophenyl)valeric acid (FPVA) and 5-(4-fluorophenoxy)valericacid (FPxVA) represented by the following Formulas (12) and (28),respectively, may still also be cultured to obtain apolyhydroxyalkanoate containing the 3HFPV and 3HFPxV monomer units.

A microorganism capable of producing a polyhydroxyalkanoate containing3-hydroxy-7-phenoxyheptanoic acid (3HPxHp) and3-hydroxy-5-phenoxyvaleric acid (3HPxV) monomer units represented by thefollowing Formulas (29) and (15), respectively, from 7-phenoxyheptanoicacid (PxHpA) represented by the following Formula (30) may also becultured to obtain a polyhydroxyalkanoate containing the 3HPxHp and3HPxV monomer units.

A more specific process is described on general items here. Onindividual items, it is described in Examples later.

Microorganism

The microorganism used in the process according to the present inventionmay be any microorganism as long as it is a microorganism capable ofproducing the polyhydroxyalkanoate containing the units represented byFormulas (2) to (4), by culturing the microorganism in a culture mediumcontaining the corresponding alkanoic acid. As an example thereof, itmay include microorganisms belonging to the genus Pseudomonas. Statedmore specifically, the microorganism may include Pseudomonas cichoriistrain YN2 (FERM BP-7375), Pseudomonas cichorii strain H45 (FERMBP-7374), Pseudomonas putida strain P91 (FERM BP-7373) and Pseudomonasjessenii strain P161 (FERM BP-7376). These four kinds of microorganismshave been deposited in Patented-Microorganism Deposition Center,Biotechnology Industrial Technology Institute of The Ministry of Economyand Industry, and are microorganisms disclosed in Japanese PatentApplication Laid-Open No. 2002-080571. Incidentally, in respect of thoseother than these strains, too, the microorganism usable in the PHAproduction process according to the present invention may also beobtained by culturing using the alkanoate as a substrate, e.g., byscreening any microorganism belonging to the genus Pseudomonas.

Details of the strains YN2, H45, P91 and P161 are shown below.

- Bacteriological Properties of Strain YN2 - (1) MorphologicalProperties Size and shape of cells: rod-shaped bacteria of 0.8 μm × 1.5to 2.0 μm. Polymorphism: no. Mobility: yes. Sporulation: no. Gramstaining: negative. Colony formation: round, entirely smooth periphery,low protrusion, smooth surface layer, glossy, semitransparent. (2)Physiological properties: Catalase: positive. Oxidase: positive. O/Ftest: oxidation type (non-fermentative). Reduction of nitrate: negative.Formation of indole: positive. Souring of D-glucose: negative. Argininedihydrolase: negative. Urease: negative. Aesculin hydrolysis: negative.Gelatin hydrolysis: negative. β-Galactosidase: negative. Fluorochromeproduction in King's B agar: positive. Growth in 4% NaCl: positive (weakgrowth). Accumulation of poly-β-hydroxybutyric negative.* acid:Hydrolysis of Tween 80: positive. (3) Substrate utilization ability:D-glucose: positive. L-arabinose: positive. D-mannose: negative.D-mannitol: negative. N-acetyl-D-glucosamine: negative. Maltose:negative. Potassium gluconate: positive. n-Capric acid: positive. Adipicacid: negative. DL-malic acid: positive. Sodium citrate: positive.Phenyl acetate: positive. - Bacteriological Properties of Strain H45 -(1) Morphological Properties Size and shape of cells: rod-shapedbacteria of 0.8 μm × 1.0 to 1.2 μm. Polymorphism: no. Mobility: yes.Sporulation: no. Gram staining: negative. Colony formation: round,entirely smooth periphery, low protrusion, smooth surface layer, glossy,cream-colored. (2) Physiological properties: Catalase: positive.Oxidase: positive. O/F test: oxidation type. Reduction of nitrate:negative. Formation of indole: negative. Souring of D-glucose: negative.Arginine dihydrolase: negative. Urease: negative. Aesculin hydrolysis:negative. Gelatin hydrolysis: negative. β-Galactosidase: negative.Fluorochrome production in King's B agar: positive. Growth in 4% NaCl:negative. Accumulation of poly-β-hydroxybutyric negative. acid: (3)Substrate utilization ability: D-glucose: positive. L-arabinose:negative. D-mannose: positive. D-mannitol: positive.N-acetyl-D-glucosamine: positive. Maltose: negative. Potassiumgluconate: positive. n-Capric acid: positive. Adipic acid: negative.DL-malic acid: positive. Sodium citrate: positive. Phenyl acetate:positive. - Bacteriological Properties of Strain P91 - (1) MorphologicalProperties Size and shape of cells: rod-shaped bacteria of 0.6 μm × 1.5μm. Polymorphism: no. Mobility: yes. Sporulation: no. Gram staining:negative. Colony formation: round, entirely smooth periphery, lowprotrusion, smooth surface layer, glossy, cream-colored. (2)Physiological properties: Catalase: positive. Oxidase: positive. O/Ftest: oxidation type. Reduction of nitrate: negative. Formation ofindole: negative. Souring of D-glucose: negative. Arginine dihydrolase:positive. Urease: negative. Aesculin hydrolysis: negative. Gelatinhydrolysis: negative. β-Galactosidase: negative. Fluorochrome productionin King's B agar: positive. (3) Substrate utilization ability:D-glucose: positive. L-arabinose: negative. D-mannose: negative.D-mannitol: negative. N-acetyl-D-glucosamine: negative. Maltose:negative. Potassium gluconate: positive. n-Capric acid: positive. Adipicacid: negative. DL-malic acid: positive. Sodium citrate: positive.Phenyl acetate: positive. - Bacteriological Properties of Strain P161 -(1) Morphological Properties Size and shape of cells: spherical, 0.6 μmdiameter. rod-shaped, 0.6 μm × 1.5 to 2.0 μm. Polymorphism: yes(elongation type) Mobility: yes. Sporulation: no. Gram staining:negative. Colony formation: round, entirely smooth periphery, lowprotrusion, smooth surface layer, pale yellow. (2) Physiologicalproperties: Catalase: positive. Oxidase: positive. O/F test: oxidationtype. Reduction of nitrate: positive. Formation of indole: negative.Souring of D-glucose: negative. Arginine dihydrolase: positive. Urease:negative. Aesculin hydrolysis: negative. Gelatin hydrolysis: negative.β-Galactosidase: negative. Fluorochrome production in King's B agar:positive. (3) Substrate utilization ability: D-glucose: positive.L-arabinose: positive. D-mannose: positive. D-mannitol: positive.N-acetyl-D-glucosamine: positive. Maltose: negative. Potassiumgluconate: positive. n-Capric acid: positive. Adipic acid: negative.DL-malic acid: positive. Sodium citrate: positive. Phenyl acetate:positive. *judged by dying a nutrient agar cultured colony with Sudanblack.

Culture Substrate

As a substrate capable of feeding acetyl-CoA or an energy source and acarbon source in the process according to the present invention, aculture medium component derived from a natural product such as yeastextract, polypeptone, meet extract (e.g., beef extract) or Casamino acidmay be used. Also usable are saccharides, organic acids occurring asintermediates in the TCA (tricarboxylic acid) cycle, and organic acidsoccurring through one-stage or two-stage biochemical reaction from theTCA cycle, or salts thereof. Any of these compounds may appropriately beselected taking account of its utility as the substrate formicroorganism to be used, as long as they are compounds capable offeeding the acetyl-CoA or energy source and carbon source withoutpassing through the β-oxidation cycle.

Where the intended bulky monomer may be in a small proportion, astraight-chain alkanoic acid having 4 to 12 carbon atoms, or a saltthereof, may also be used as the substrate. In such as case, however,attention must be paid to the fact that a straight-chain andsubstituent-free, simple monomer (hereinafter simply “mcl”) is in alarger proportion.

Of these, the saccharides may include aldoses such as glyceraldehyde,erythrose, arabinose, xylose, glucose, galactose, mannose and fructose;alditols such as glycerol, erythritol and xylitol; aldones such asgluconic acid; uronic acids such as glucuronic acid and galacturonicacid; and disaccharides such as maltose, sucrose and lactose. At leastone compound selected from these may preferably be used.

The organic acids or salts thereof may include, as examples thereof,pyruvic acid, oxalacetic acid, citric acid, isocitric acid, ketoglutaricacid, succinic acid, fumaric acid, malic acid and lactic acid, or saltsof these, and at least one compound selected from these may preferablybe used.

The amino acids or salts thereof may include glutamic acid and asperticacid, or salts of these, and at least one compound selected from thesemay preferably be used.

In particular, it is preferable to use polypeptone and saccharides. Ofthe saccharides, at least one selected from the group consisting ofglucose, fructose and mannose is preferred. Any of these substrates mayusually preferably be contained in a proportion of from 0.1% to 5%(w/v), and more preferably from 0.2% to 2% (w/v), per culture medium.

Culturing; General

The intended PHA may be produced by culturing any of thesemicroorganisms in a culture medium containing the alkanoate forintroducing the desired monomer unit and the substrate for proliferationaccording to the present invention. Such a PHA is an isotactic polymer,which is commonly constituted of only the R-configuration.

For the usual culturing of microorganisms used in the PHA productionprocess according to the present invention, e.g., for the preparation ofstorage strains and for the proliferation to ensure the number ofmicroorganism and active state, any type of culture mediums such ascommonly available natural culture mediums and synthetic mediums towhich nutrient sources have been added may be used as long as they donot adversely affect the growth and existence of microorganisms.Culturing conditions such as temperature, aeration and spinning mayappropriately be selected in accordance with microorganisms to be used.

As for the case in which the PHA is produced and accumulated using themicroorganism, an inorganic culture medium containing the alkanoate forintroducing the desired monomer unit may be used as a culture medium forthe production of PHA.

The inorganic culture medium used in the above culturing method may beany of those which contain ingredients with which the microorganism canbe proliferated, such as a phosphorus source (e.g., phosphate) and anitrogen source (e.g., ammonium salt or nitrate). For example, theinorganic culture medium may include MSB medium, E medium (J. Biol.Chem., 218, 97-106, 1956), M9 medium, and others.

Composition of the M9 medium, used in Examples of the present invention,is shown below.

Na₂HPO₄ 6.2 g KH₂HPO₄ 3.0 g NaCl 0.5 g NH₄Cl 1.0 g(in 1 liter of the culture medium; pH: 7.0)

The culturing may be carried out under conditions of, e.g., 15° C. to40° C., and preferably from 20° C. to 35° C., and by shaking culture orspinner culture under aerobic conditions.

In the step of culturing, any methods used in the usual culturing ofmicroorganisms may be used, as exemplified by batch culture, flow batchculture, semicontinuous culture, continuous culture and reactor typeculture. A multi-stage method in which any of these steps are connectedin a plurality of stages may also be employed.

Specific culturing steps are described below on the respectiveproliferation substrates used in the present invention.

Culturing; mcl-Alkanoate

For example, as a method comprising a two-stage culturing process, amethod is available in which, in the first stage, in an inorganicculture medium which contains, as a substrate for proliferation,approximately from 0.1% by weight to 0.2% by weight of an alkanoatehaving 6 to 12 carbon atoms as exemplified by octanoic acid or nonanoicacid and contains approximately from 0.01% to 0.5% of an alkanoate forintroducing the desired monomer unit, the microorganism is cultured fromthe latter phase of logarithmic growth up to a point of time of thestationary phase, and, in the second stage, the bacterial body formed oncompletion of the culturing in the first stage is collected bycentrifugation or the like and thereafter further cultured in a culturemedium which contains approximately from 0.01% by weight to 0.5% byweight of that alkanoate and in which any nitrogen source is notpresent, where, after the culturing has been completed, the bacterialbody is collected and the desired PHA is extracted.

Another method is also available in which the microorganism is culturedby supplying approximately from 0.1% by weight to 0.2% by weight of analkanoate having 6 to 12 carbon atoms as exemplified by octanoic acid ornonanoic acid and approximately from 0.01% by weight to 0.5% by weightof an alkanoate for introducing the desired monomer unit, and thebacterial body formed is collected from the latter phase of logarithmicgrowth up to a point of time of the stationary phase, where the desiredPHA is extracted.

Here, in the method in which as the substrate for proliferation themcl-alkanoate is added to the culture medium, the PHA gained stands aPHA in which monomer units derived from the mcl-alkanoate added as thesubstrate for proliferation are mixedly present in a large quantity.Such a PHA is an isotactic polymer, which is commonly constituted ofonly the R-configuration.

Culturing; Saccharide

For example, as a method comprising a two-stage culturing process, amethod is available in which, in the first stage, in an inorganicculture medium which contains, as a substrate for proliferation,approximately from 0.1% by weight to 2.0% by weight of a saccharide(e.g., glucose, mannose or fructose) and contains approximately from0.01% by weight to 0.5% by weight of an alkanoate for introducing thedesired monomer unit, the microorganism is cultured from the latterphase of logarithmic growth up to a point of time of the stationaryphase, and, in the second stage, the bacterial body formed on completionof the culturing in the first stage is collected by centrifugation orthe like and thereafter further cultured in a culture medium whichcontains, as a substrate for proliferation, approximately from 0.1% byweight to 2.0% by weight of a saccharide (e.g., glucose, mannose orfructose) and contains approximately from 0.01% by weight to 0.5% byweight of that alkanoate and in which any nitrogen source is notpresent, where, after the culturing has been completed, the bacterialbody is collected and the desired PHA is extracted.

Another method is also available in which the microorganism is culturedby supplying approximately from 0.1% by weight to 2.0% by weight of asaccharide (e.g., glucose, mannose or fructose) as a substrate forproliferation and approximately from 0.01% by weight to 0.5% by weightof an alkanoate for introducing the desired monomer unit, and thebacterial body formed is collected from the latter phase of logarithmicgrowth up to a point of time of the stationary phase, where the desiredPHA is extracted.

Thus, the concentration of the saccharide (e.g., glucose, mannose orfructose) to be added to the culture medium may appropriately beselected in accordance with the type of the alkanoate for introducingthe desired monomer unit, the genus of the microorganism, the density ofthe bacterial body or the culturing method. Usually, the saccharide maybe added selecting its content in the culture medium in the range ofapproximately from 0.1% by weight to 2.0% by weight. As for theconcentration of the alkanoate serving as a raw material, it may alsoappropriately be selected in accordance with the genus of themicroorganism, the density of the bacterial body or the culturingmethod. Usually, the alkanoate may be added selecting its content in theculture medium in the range of approximately from 0.01% by weight to0.5% by weight. Thus, as a result of the culturing of a microorganism inthe culture medium which contains the saccharide (e.g., glucose, mannoseor fructose) and the alkanoate, the desired PHA is produced andaccumulated, in which any unintended monomer units are less mixedlypresent or not present at all. Such a PHA is an isotactic polymer, whichis commonly constituted of only the R-configuration.

Culturing; Polypeptone

For example, as a method comprising a two-stage culturing process, amethod is available in which, in the first stage, in an inorganicculture medium which contains, as a substrate for proliferation,approximately from 0.1% by weight to 2.0% by weight of polypeptone andcontains approximately from 0.01% by weight to 0.5% by weight of analkanoate for introducing the desired monomer unit, the microorganism iscultured from the latter phase of logarithmic growth up to a point oftime of the stationary phase, and, in the second stage, the bacterialbody formed on completion of the culturing in the first stage iscollected by centrifugation or the like and thereafter further culturedin a culture medium which contains approximately from 0.01% by weight to0.5% by weight of that alkanoate and in which any nitrogen source is notpresent, where, after the culturing has been completed, the bacterialbody is collected and the desired PHA is extracted.

Another method is also available in which the microorganism is culturedby supplying approximately from 0.1% by weight to 2.0% by weight ofpolypeptone and approximately from 0.01% by weight to 0.5% by weight ofan alkanoate for introducing the desired monomer unit, and the bacterialbody formed is collected from the latter phase of logarithmic growth upto a point of time of the stationary phase, where the desired PHA isextracted.

Thus, the concentration of the polypeptone to be added to the culturemedium may appropriately be selected in accordance with the type of thealkanoate for introducing the desired monomer unit, the genus of themicroorganism, the density of the bacterial body or the culturingmethod. Usually, the polypeptone may be added selecting its content inthe culture medium in the range of approximately from 0.1% by weight to2.0% by weight. Also, as the polypeptone, any commercially availablepolypeptone used generally for the culturing of microorganisms maypreferably be used. As for the concentration of the alkanoate serving asa raw material, it may also appropriately be selected in accordance withthe genus of the microorganism, the density of the bacterial body or theculturing method. Usually, the alkanoate may be added selecting itscontent in the culture medium in the range of approximately from 0.01%by weight to 0.5% by weight. Thus, as a result of the culturing of amicroorganism in the culture medium which contains the polypeptone andthe alkanoate, the desired PHA is produced and accumulated, in which anyunintended monomer units are less mixedly present or not present at all.Such a PHA is an isotactic polymer, which is commonly constituted ofonly the R-configuration.

Culturing; Organic Acid Participating in TCA Cycle

For example, as a method comprising a two-stage culturing process, amethod is available in which, in the first stage, in an inorganicculture medium which contains, as a substrate for proliferation,approximately from 0.1% by weight to 2.0% by weight of an organic acidparticipating in the TCA cycle (e.g., lactic acid, pyruvic acid, citricacid, succinic acid, fumaric acid or malic acid, or a salt thereof) andcontains approximately from 0.01% by weight to 0.5% by weight of analkanoate for introducing the desired monomer unit, the microorganism iscultured from the latter phase of logarithmic growth up to a point oftime of the stationary phase, and, in the second stage, the bacterialbody formed on completion of the culturing in the first stage iscollected by centrifugation or the like and thereafter further culturedin a culture medium which contains, as a substrate for proliferation,approximately from 0.1% by weight to 2.0% by weight of an organic acidparticipating in the TCA cycle (e.g., lactic acid, pyruvic acid, citricacid, succinic acid, fumaric acid or malic acid, or a salt thereof) andcontains approximately from 0.01% by weight to 0.5% by weight of thatalkanoate and in which any nitrogen source is not present, where, afterthe culturing has been completed, the bacterial body is collected andthe desired PHA is extracted.

Another method is also available in which the microorganism is culturedby supplying approximately from 0.1% by weight to 2.0% by weight of anorganic acid participating in the TCA cycle (e.g., lactic acid, pyruvicacid, citric acid, succinic acid, fumaric acid or malic acid, or a saltthereof) and approximately from 0.01% by weight to 0.5% by weight of analkanoate for introducing the desired monomer unit, and the bacterialbody formed is collected from the latter phase of logarithmic growth upto a point of time of the stationary phase, where the desired PHA isextracted.

Thus, the concentration of the organic acid participating in the TCAcycle (e.g., lactic acid, pyruvic acid, citric acid, succinic acid,fumaric acid or malic acid, or a salt thereof) to be added to theculture medium may appropriately be selected in accordance with the typeof the alkanoate for introducing the desired monomer unit, the genus ofthe microorganism, the density of the bacterial body or the culturingmethod. Usually, the organic acid may be added selecting its content inthe culture medium in the range of approximately from 0.1% by weight to2.0% by weight. As for the concentration of the alkanoate serving as araw material, it may also appropriately be selected in accordance withthe genus of the microorganism, the density of the bacterial body or theculturing method. Usually, the alkanoate may be added selecting itscontent in the culture medium in the range of approximately from 0.01%by weight to 0.5% by weight. Thus, as a result of the culturing of amicroorganism in the culture medium which contains the organic acidparticipating in the TCA cycle (e.g., lactic acid, pyruvic acid, citricacid, succinic acid, fumaric acid or malic acid, or a salt thereof) andthe alkanoate, the desired PHA is produced and accumulated, in which anyunintended monomer units are less mixedly present or not present at all.Such a PHA is an isotactic polymer, which is commonly constituted ofonly the R-configuration.

Culturing; Polypeptone+Pyruvic Acid or Salt Thereof

For example, as a method comprising a two-stage culturing process, amethod is available in which, in the first stage, in an inorganicculture medium which contains, as a substrate for proliferation,approximately from 0.1% by weight to 2.0% by weight of polypeptone andcontains approximately from 0.01% by weight to 0.5% by weight of analkanoate for introducing the desired monomer unit, the microorganism iscultured from the latter phase of logarithmic growth up to a point oftime of the stationary phase, and, in the second stage, the bacterialbody formed on completion of the culturing in the first stage iscollected by centrifugation or the like and thereafter further culturedin an inorganic culture medium which contains, as a substrate forproliferation, approximately from 0.1% by weight to 2.0% by weight ofpyruvic acid or a salt thereof and contains approximately from 0.01% byweight to 0.5% by weight of that alkanoate and in which any nitrogensource is not present, where, after the culturing has been completed,the bacterial body is collected and the desired PHA is extracted.

Thus, the concentration of the polypeptone and pyruvic acid or a saltthereof which are to be added to the culture medium may appropriately beselected in accordance with the type of the alkanoate for introducingthe desired monomer unit, the genus of the microorganism, the density ofthe bacterial body or the culturing method. Usually, each of thepolypeptone and the pyruvic acid or a salt thereof may be addedselecting its content in the culture medium in the range ofapproximately from 0.1% by weight to 2.0% by weight. As for theconcentration of the alkanoate serving as a raw material, it may alsoappropriately be selected in accordance with the genus of themicroorganism, the density of the bacterial body or the culturingmethod. Usually, the alkanoate may be added selecting its content in theculture medium in the range of approximately from 0.01% by weight to0.5% by weight. Thus, as a result of the two-stage culturing of amicroorganism in the culture medium which contains the polypeptone andthe alkanoate and in the culture medium which contains the pyruvic acidor a salt thereof and the alkanoate, the desired PHA is produced andaccumulated, in which any unintended monomer units are less mixedlypresent or not present at all. Such a PHA is an isotactic polymer, whichis commonly constituted of only the R-configuration.

Collection of PHA

To gain the PHA from the culture solution according to the presentinvention, conventionally available methods may be used. Where the PHAis secreted in the culture solution, a method may be used in which it isextracted from the culture solution and purified, and, where the PHA isaccumulated in the bacterial body, a method in which it is extractedfrom the bacterial body and purified. For example, for the collection ofthe PHA from the cultured bacterial body of a microorganism, extractionwith an organic solvent such as chloroform is most simple, which isconventionally made. Besides the chloroform, dioxane, tetrahydrofuran,acetonitrile or acetone is used in some cases. Also, in an environmentwhich should be kept from use of organic solvents, a method may be usedin which bacterial-body components other than the PHA are removed tocollect the PHA, by treating microorganism cells with a surface-activeagent such as SDS (sodium dodecyl sulfate), treating them with an enzymesuch as lysozyme, or treating them with a chemical such as EDTA(ethylenediaminetetraacetic acid), sodium hypochlorite, hydrogenperoxide, ammonium, and so on.

The culturing of microorganisms according to the present invention, theproduction of the PHA by microorganisms and its accumulation in thebacterial body, and the collection of the PHA from the bacterial bodyare by no means limited to the above methods. For example, as themicroorganism utilized in the PHA production process according to thepresent invention, besides the four kinds of strains describedpreviously, usable are any microorganisms having the ability to producethe PHA according to the present invention, like these four kinds ofstrains.

Other Constituent Materials

Other constituent materials which constitute the toner for developingelectrostatic latent images according to the present invention aredescribed below. The toner for developing electrostatic latent images isconstituted of, in addition to the binder resin described above, acolorant, a charge control agent and other additives which areoptionally added.

Binder Resin

First, as the binder resin, only the binder resin of the presentinvention may preferably be used. In addition to the binder resin of thepresent invention, other thermoplastic resin may be incorporated as abinder resin. For example, the former may be used in the form of itsmixture with one or more of styrene type polymers such as polystyrene,polyacrylate and a styrene-acrylate copolymer, polyvinyl chloride,polyvinyl acetate, polyvinylidene chloride, phenolic resins, epoxyresins and polyester resins, and any resins may be used without anyparticular limitations as long as they are those usually used whentoners are produced.

Where a thermoplastic resin having no biodegradability is used as thebinder resin other than the PHA, such an additional thermoplastic resinmay preferably be mixed in a proportion of 80% by weight or less, andparticularly 50% by weight or less. If the additional thermoplasticresin is in a proportion larger than 80% by weight, the additionalthermoplastic resin may have so excessively a high binding strength tothe paper surface that the toner may have low deinking properties. Also,where the toner is used as a biodegradable toner, it is preferable notto use such an additional thermoplastic resin having nobiodegradability.

In the present invention, any commercially available biodegradableplastic of various types may also preferably be mixed and used. Thebiodegradable plastic may include, e.g., ECOSTAR and ECOSTAR PLUS (tradenames; available from Hagiwara Kogyo), BIOPOLE (trade name; availablefrom I.C.I Japan), AJICOAT (trade name; available from Ajinomoto),PLACCELL and GPOLYCAPROLACTONE (trade names; available from DaicellChemical), SHOREX and BIONORE (trade names; available from Showa Denko),LACTY (trade name; available from Shimadzu Corporation), and RAYCIA(trade name; available from Mitsui Chemical). In the case when any ofthese resins are mixed and used, the biodegradability inherent in thetoner of the present invention is not damaged.

Of these, the polycaprolactone (i.e., a polymer of ε-caprolactone) orthe polylactic acid referred to previously is particularly preferred inview of advantages that it is completely degradable with ease by lipase,esterase or the like and it can readily be blended with other resins, ormodified in physical properties by copolymerization or the like.

The styrene type polymers may include copolymers of styrene withacrylate or methacrylate and copolymers of other monomerscopolymerizable with these, and copolymers of styrene with dienemonomers (such as butadiene and isoprene) and copolymers of othermonomers copolymerizable with these. The polyester type polymers mayinclude polycondensation products of aromatic dicarboxylic acids withalkylene oxide addition products of aromatic diols. The epoxy typepolymers may include reaction products of aromatic diols withepichlorohydrin, and modified products thereof. The polyolefin typepolymers may include polyethylene, polypropylene, and copolymers of anyof these with other copolymerizable monomers. The polyurethane typepolymers may include polyaddition products of aromatic diisocyanateswith alkylene oxide addition products of aromatic diols.

As specific examples of the binder resin usable in the form of a mixturewith the binder resin of the present invention, it may include polymersof the following polymerizable monomers, or mixtures of any of these, orcopolymerization products obtained using two or more of the followingpolymerizable monomers. Such resins may specifically include, e.g.,styrene type polymers such as styrene-methacrylic acid type polymers, aswell as the polyester type polymers, epoxy type polymers, polyolefintype polymers and polyurethane type polymers.

As specific examples of the polymerizable monomers, it may include,e.g., styrene; styrene derivatives such as o-methylstyrene,m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene,p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrenee,2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene,p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyreneand p-n-dodecylstyrene; ethylene unsaturated monoolefins such asethylene, propylene, butylene and isobutylene; unsaturated polyenes suchas butadiene; vinyl halides such as vinyl chloride, vinylidene chloride,vinyl bromide and vinyl fluoride; vinyl esters such as vinyl acetate,vinyl propionate and vinyl benzoate; α-methylene aliphaticmonocarboxylates such as methyl methacrylate, ethyl methacrylate, propylmethacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octylmethacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearylmethacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate anddiethylaminoethyl methacrylate; acrylic esters such as methyl acrylate,ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate,n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearylacrylate, 2-chloroethyl acrylate and phenyl acrylate; vinyl ethers suchas methyl vinyl ether, ethyl vinyl ether and isobutyl vinyl ether; vinylketones such as methyl vinyl ketone, hexyl vinyl ketone and methylisopropenyl ketone; N-vinyl compounds such as N-vinylpyrrole,N-vinylcarbazole, N-vinylindole and N-vinylpyrrolidone;vinylnaphthalenes; acrylic acid or methacrylic acid derivatives such asacrylonitrile, methacrylonitrile and acrylamide; esters of the above α,β-unsaturated acids and diesters of dibasic acids; dicaroxylic acidssuch as maleic acid, methyl maleate, butyl maleate, dimethyl maleate,phthalic acid, succinic acid and terephthalic acid; polyol compoundssuch as ethylene glycol, diethylene glycol, triethylene glycol,1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol,1,6-hexanediol, bisphenol A, hydrogenated bisphenol A andpolyoxyethylene type bisphenol A; isocyanates such asp-phenylenediisocyanate, p-xylylenediisocyanate and1,4-tetramethylenediisocyanate; amines such as ethylamine, butylamine,ethylenediamine, 1,4-diaminobenzene, 1,4-diaminobutane andmonoethanolamine; and epoxy compounds such as diglycidyl ether, ethyleneglycol diglycidyl ether, bisphenol-A diglycidyl ether and hydroquinonediglycidyl ether.

Cross-linking Agent

When the binder resin usable in the form of a mixture with the binderresin of the present invention is made up, a cross-linking agent asshown below may optionally be used.

For example, it may include, as bifunctional cross-linking agents,divinylbenzene, bis(4-acryloxypolyethoxyphenyl)propane, ethylene glycoldiacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate,1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycoldiacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate,tetraethylene glycol diacrylate, polyethylene glycol #200 diacrylate,polyethylene glycol #400 diacrylate, polyethylene glycol #600diacrylate, dipropylene glycol diacrylate, polypropylene glycoldiacrylate, polyester type diacrylates (MANDA, trade name; availablefrom Nippon Kayaku Co., Ltd.), and the above diacrylates whose acrylatemoiety has been replaced with methacrylate.

As trifunctional or more, polyfunctional cross-linking agents it mayinclude, e.g., pentaerythritol triacrylate, trimethylolethanetriacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, oligoester acrylate, and these compounds whose acrylatemoiety has been replaced with methacrylate, and also2,2-bis(4-methacyloxypolyethoxyphenyl)propane, diallyl phthalate,triallyl cyanurate, triallyl asocyanurate triallyl isocyanurate,triallyl trimellitate and diaryl chlorendate.

Polymerization Initiator

When the binder resin usable in the form of a mixture with the binderresin of the present invention is made up, a polymerization initiator asshown below may also optionally be used.

For example, it may include di-t-butyl peroxy-2-ethylhexanoate, cuminperpivalate, t-butyl peroxylaurate, benzoyl peroxide, lauroyl peroxide,octanoyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumylperoxide, 2,2′-azobis(2-isobutyronitrile),2,2′-azobis(2-methylbutyronitrile),2,2′-azobis(2,4-dimethylvaleronitrile),2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile),1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane,1,1-bis(t-butylperoxy)cyclohexane,1,4-bis(t-butylperoxycarbonyl)cyclohexane, 2,2-bis(t-butylperoxy)octane,n-butyl-4,4-bis(t-butylperoxy) valylate, 2,2-bis(t-butylperoxy)butane,1,3-bis(t-butylperoxy-isopropyl)benzene,2,5-dimethyl-2,5-di(t-butylperoxy)hexane,2,5-dimethyl-2,5-di(t-butylperoxy) hexane,2,5-dimethyl-2,5-di(benzoylperoxy)hexane, di-t-butyl peroxyisbphthalate,2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane,di-t-butylperoxy-(-methylsuccinate, di-t-butyl peroxydimethylglutarate,di-t-butyl peroxyhexahydroterephthalate, di-t-butyl peroxyazelate,2,5-diemthyl-2,5-di(t-butylperoxy)hexane, diethyleneglycol-bis(t-butylperoxycarbonate), di-t-butyl peroxytrimethyladipate,tris(t-butylperoxy)triazine and vinyl tris(t-butylperoxy)silane. Any ofthese may used alone or in combination. The initiator may be used in anamount of not less than 0.05 part by weight, and preferably from 0.1part by weight to 15 parts by weight, based on 100 parts by weight ofthe monomer.

Colorant

As the colorant that constitutes the toner for developing electrostaticlatent images according to the present invention, any colorants may beused without any particular limitations as long as they are thoseusually used when toners are produced. All pigments and/or dyes may beused, as exemplified by carbon black, titanium white, monoazo type redpigments, disazo type yellow pigments, quinacridone type magentapigments and anthraquinone type dyes.

Stated more specifically, when the toner for developing electrostaticlatent images according to the present invention is used as a magneticcolor toner, the colorant may include, e.g., C.I. Direct Red 1, C.I.Direct Red 4, C.I. Acid Red 1, C.I. Basic Red 1, C.I. Mordant Red 30,C.I. Direct Blue 1, C.I. Direct Blue 2, C.I. Acid Blue 9, C.I. Acid Blue15, C.I. Basic Blue 3, C.I. Basic Blue 5, C.I. Mordant Blue 7, C.I.Direct Green 6, C.I. Basic Green 4 and C.I. Basic Green 6. As thepigments, usable are chrome yellow, cadmium yellow, mineral fast yellow,navel yellow, Naphthol Yellow S, Hanza Yellow G, Permanent Yellow NCG,Tartrazine Yellow Lake, chrome orange, molybdenum orange, PermanentOrange GTR, Pyrazolone Orange, Benzidine Orange G, cadmium red,Permanent Red 4R, Watching Red calcium salt, Eosine Lake, BrilliantCarmine 3B, manganese violet, Fast Violet B, Methyl Violet Lake,Prussian blue, cobalt blue, Alkali Blue Lake, Victoria Blue Lake,Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue BC, chrome green,chromium oxide, Pigment Green B, Malachite Green Lake, Final YellowGreen G and so forth.

When the toner for developing electrostatic latent images according tothe present invention is used as toners for full-color two-componentdevelopers, those shown below may be used as colorants. For example,color pigments for a magenta toner may include, C.I. Pigment Red 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23,30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58,60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 163, 202,206, 207, 209; C.I. Pigment Violet 19; and C.I. Vat Red 1, 2, 10, 13,15, 23, 29, 35.

In the present invention, any of the pigments listed above may be usedalone, or dyes may be used in combination with such pigments so thatcolor sharpness can be improved. This is preferable in view of imagequality of full-color images. Magenta dyes usable in such a case mayinclude oil-soluble dyes such as C.I. Solvent Red 1, 3, 8, 23, 24, 25,27, 30, 49, 81, 82, 83, 84, 100, 109, 121, C.I. Disperse Red 9, C.I.Solvent Violet 8, 13, 14, 21, 27, and C.I. Disperse Violet 1; and basicdyes such as C.I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24,27, 29, 32, 34, 35, 36, 37, 38, 39, 40, and C.I. Basic Violet 1, 3, 7,10, 14, 15, 21, 25, 26, 27, 28.

As other color pigments, cyan color pigments may include C.I. PigmentBlue 2, 3, 15, 16, 17, C.I. Vat Blue 6, C.I. Acid Blue 45, or copperphthalocyanine pigments whose phthalocyanine skeleton has beensubstituted with 1 to 5 phthalimide methyl group(s).

Yellow color pigments may include C.I. Pigment Yellow 1, 2, 3, 4, 5, 6,7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 83, and C.I. Vat Yellow1, 3, 20.

The dyes and pigments as described above may each be used alone.Otherwise, any of them may arbitrarily be mixed and then used, in orderto obtain the desired color tone of toners.

Taking account of the environmental conservation and the safety to humanbodies, water-insoluble food dyes such as food lakes of various typesmay preferably be used, which may include, e.g., food red No.40 aluminumlake, food red No.2 aluminum lake, food red No.3 aluminum lake, food redNo.106 aluminum lake, food yellow No.5 aluminum lake, food yellow No.4aluminum lake, food blue No.1 aluminum lake and food blue No.2 aluminumlake.

The above water-insoluble food dyes may also function as charge controlagents. In such a case, as charge control agents for negative charging,the above aluminum lakes may preferably be used. Thus, in the case whenthe water-insoluble food dyes have the function of charge controlagents, they not only can improve the environmental safety of toners,but also can contribute to the cost reduction of toners.

The content of the above colorant in the toner may be changed in a widerange in accordance with the desired coloring effect and so forth.Usually, in order to attain the best toner characteristics, i.e., takingaccount of coloring power for printing, shape stability of tonerparticles, toner scattering and so forth, any of these colorants mayusually be used in an amount of from 0.1 to 60 parts by weight, andpreferably from 0.5 to 20 parts by weight, based on 100 parts by weightof the binder resin.

Charge Control Agent

As the charge control agent, any charge control agent usedconventionally may be used. As specific examples, it may includenigrosine type dyes and quaternary ammonium salt or monoazo type metalcomplex salt dyes. The quantity of the charge control agent to be usedmay be determined taking account of conditions such as the chargeabilityof the binder resin, the quantity of the colorant to be added, themethod of production inclusive of a dispersion method and thechargeability of other additives. The charge control agent may be usedin a proportion of from 0.1 to 20 parts by weight, and preferably from0.5 to 10 parts by weight, based on 100 parts by weight of the binderresin. Besides this, inorganic particles such as metal oxide particlesor an inorganic material surface-treated with an organic material mayalso be used. Any of these charge control agents may be so used as to bemixed in the binder resin, or may be used in such a form that it hasadhered to toner particle surfaces.

Other Components of Toner

In the toner for developing electrostatic latent images according to thepresent invention, in addition to the binder resin and colorantcomponents described above, the following compounds may be added. Suchcompounds are exemplified by silicone resin, polyester, polyurethane,polyamide, epoxy resin, polyvinyl butyral, rosin, modified rosin,terpene resin, phenolic resin, aliphatic hydrocarbon resin such aslow-molecular weight polyethylene or low-molecular weight polypropyleneor alicyclic hydrocarbon resin, aromatic petroleum resin and chlorinatedparaffin or paraffin wax. Waxes preferably usable among these mayspecifically include low-molecular weight polypropylene and by-productsthereof, low-molecular weight polyester, ester waxes, and aliphaticderivatives. Waxes obtained from these waxes by fractionating the waxesby various methods may also preferably be used. Also, after thefractionation, the waxes may be subjected to oxidation, blockcopolymerization or graft modification.

In the toner for developing electrostatic latent images according to thepresent invention, a toner having superior performance can be obtainedespecially when it contains the above wax component and such a waxcomponent stands dispersed in the binder resin in the form of sphericaland/or spindle-shaped islands in its cross-sectional observation oftoner particles using a transmission electron microscope (TEM).

Toner Production Process

As a specific process for producing the toner for developingelectrostatic latent images according to the present invention,constituted as described above, any conventionally known process may beused. The toner for developing electrostatic latent images according tothe present invention may be produced by, e.g., what is called apulverization process, which produces the toner according to thefollowing steps. That is, stated specifically, resins such as the binderresin of the present invention, and other components such as the chargecontrol agent and the wax which are optionally added are thoroughlymixed by means of a mixing machine such as a Henschel mixer or a ballmill, and then the mixture is melt-kneaded using a heat kneading machinesuch as a heating roll, a kneader or an extruder to make the resin andso on melt one another, in which the pigment, dye or magnetic materialas the colorant and additives such as a metal compound optionally addedare then dispersed or dissolved, followed by cooling for solidification.Thereafter, the solidified product is pulverizes by means of a grindingmachine such as a jet mill or a ball mill, followed by classification.Thus, the toner for developing electrostatic latent images according tothe present invention, having the desired particle diameter, can beobtained. Incidentally, in the step of classification, a multi-divisionclassifier may preferably be used in view of production efficiency.

The toner for developing electrostatic latent images according to thepresent invention, having the desired particle diameter, may also beobtained by mixing the binder resin and the charge control agent in theform of a solution using a solvent (including aromatic hydrocarbons suchas toluene and xylene, halogenated products such as chloroform andethylene dichloride, ketones such as acetone and methyl ethyl ketone,and amides such as dimethylformamide), stirring the solution, andthereafter introducing the resultant solution into water to effectreprecipitation, followed by filtration and then drying, and thereafterpulverizing the solidified product by means of a grinding machine suchas a jet mill or a ball mill, followed by classification. Incidentally,in the step of classification, a multi-division classifier maypreferably be used in view of production efficiency.

The toner for developing electrostatic latent images according to thepresent invention may still also be produced by what is called apolymerization process as described below. That is, in this case,materials such as a polymerizable monomer of the binder resin accordingto the present invention, the pigment, dye or magnetic material as thecolorant, and optionally the cross-linking agent, the polymerizationinitiator, the wax and other additives are mixed and dispersed toprepare a polymerizable monomer composition, which is then subjected tosuspension polymerization in an aqueous dispersion medium in thepresence of surfactant to synthesize polymerized color resin particles.The resin particles thus obtained are solid-liquid separated, followedby drying and then optionally classification to obtain the toner fordeveloping electrostatic latent images according to the presentinvention.

Silica External Additive

In the present invention, to the toner produced by the process asdescribed above, it is preferable to add a fine silica powder in orderto improve toner's charging stability, developing performance, fluidityand running performance. As the fine silica powder used here, a finesilica powder having a specific surface area of 20 m²/g or more, andparticularly in the range of from 30 to 400 m²/g, as measured bynitrogen adsorption according to the BET method, gives good results. Inthis case, the fine silica powder may be used in an amount of from 0.01to 8 parts by weight, and preferably from 0.1 to 5 parts by weight,based on 100 parts by weight of the toner particles. For the purpose ofmaking hydrophobic and controlling chargeability, the fine silica powderused here may preferably optionally be treated with a treating agentsuch as a silicone varnish, a modified silicone varnish of varioustypes, a silicone oil, a modified silicone oil of various types, asilane coupling agent, a silane coupling agent having a functional groupor other organosilicon compound. Use of such a treated powder ispreferred. Any of these treating agents may be used in the form of amixture.

Inorganic Powder

In order to improve toner's developing performance and runningperformance, it is also preferable to add the following inorganicpowder. It may include, e.g., oxides of metals such as magnesium, zinc,aluminum, cerium, cobalt, iron, zirconium, chromium, manganese,strontium, tin and antimony; composite metal oxides such as calciumtitanate, magnesium titanate and strontium titanate; metal salts such ascalcium carbonate, magnesium carbonate and aluminum carbonate; clayminerals such as kaolin; phosphoric acid compounds such as apatite;silicon compounds such as silicon carbide and silicon nitride; andcarbon powders such as carbon black and graphite powder. In particular,fine powder of zinc oxide, aluminum oxide, cobalt oxide, manganesedioxide, strontium titanate or magnesium titanate may preferably beused.

Lubricant

A lubricant powder as shown below may also be added to the toner. It mayinclude, e.g., fluorine resins such as Teflon and polyvinylidenefluoride; fluorine compounds such as carbon fluoride; fatty acid metalsalts such as zinc stearate; fatty acids, and fatty acid derivativessuch as fatty esters; and molybdenum sulfide.

These constituents, the binder resin usable in the form of a mixturewith the binder resin of the present invention, colorant, charge controlagent and other additives optionally added, are each in a very smallcontent in the toner. However, taking account of post-disposal, it ismore preferable to use those having biodegradability.

Carrier

The toner for developing electrostatic latent images according to thepresent invention, constituted as described above, may be used alone asa non-magnetic one-component developer, or may be applied toconventionally known various toners such as a non-magnetic toner whichconstitutes a magnetic two-component developer together with a magneticcarrier, and a magnetic toner used alone as a magnetic one-componentdeveloper. Here, as a carrier used in two-component development, any ofconventionally known carriers may be used. Stated specifically,particles formed of metals such as iron, nickel, cobalt, manganese,chromium and rare earth elements, and alloys or oxides thereof, havingbeen surface-oxidized or unoxidized and having an average particlediameter of from 20 to 300 μm, may be used. Also, it is preferable touse carriers comprising such carrier particles to or on the surfaces ofwhich a material such as a styrene resin, an acrylic resin, a siliconeresin, a fluorine resin or a polyester resin has been made to adhere orcoated.

Magnetic Toner

The toner for developing electrostatic latent images according to thepresent invention may also be made usable as a magnetic toner byincorporating a magnetic material into toner particles. In this case,the magnetic material may also be made to serve as the colorant. Themagnetic material used here may include iron oxides such as magnetite,hematite and ferrite; magnetic metals such as iron, cobalt and nickel,or alloys of any of these metals with a metal such as aluminum, cobalt,copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth,cadmium, calcium, manganese, selenium, titanium, tungsten or vanadium,and mixtures of any of these. As these magnetic material usable in thepresent invention, those having an average particle diameter of from 2μm or less, and preferably approximately from 0.1 to 0.5 μm, arepreferred. As its quantity in which it is incorporated in the toner, itmay preferably be used in an amount of from 20 to 200 parts by weightbased on 100 parts by weight of the binder resin, and particularly in anamount of from 40 to 150 parts by weight based on 100 parts by weight ofthe binder resin.

In order to achieve much higher image quality, it must be made possibleto develop finer latent image dots faithfully. For that end, it ispreferable that, e.g., the toner for developing electrostatic latentimages according to the present invention has toner particles soregulated as to have a weight-average particle diameter of from 4 μm to9 μm. Namely, toner particles having a weight-average particle diametersmaller than 4 μm are not preferable because they may cause a loweringof transfer efficiency and hence transfer residual toner tends to remainon the photosensitive member in a large quantity, tending to causenon-uniform or uneven images due to fog and faulty transfer. Also, tonerparticles having a weight-average particle diameter larger than 9 μmtend to cause spots around characters or line images.

In the present invention, the average particle diameter and particlesize distribution of the toner are measured with a Coulter counter ModelTA-II or Coulter Multisizer (manufactured by Coulter Electronics, Inc.).An interface (manufactured by Nikkaki k. k.) that outputs numberdistribution and volume distribution and a personal computer PC9801(manufactured by NEC.) are connected. As an electrolytic solution usedin the measurement, an aqueous 1% NaCl solution is prepared usingfirst-grade sodium chloride. For example, commercially available, ISOTONR-II (available from Coulter Scientific Japan Co.) may be used. As aspecific method, measurement is made by adding as a dispersant from 0.1to 5 mL of a surface active agent (preferably an alkylbenzene sulfonate)to from 100 to 150 ml of the above aqueous electrolytic solution, andfurther adding from 2 to 20 mg of a sample to be measured. Theelectrolytic solution in which the sample has been suspended issubjected to dispersion for about 1 minute to about 3 minutes in anultrasonic dispersion machine. The volume distribution and numberdistribution are calculated by measuring the volume and number of tonerparticles with particle diameters of not smaller than 2 μm by means ofthe above Coulter counter Model TA-II, using an aperture of 100 μm asits aperture. Then the values according to the present invention aredetermined, which are the volume-based, weight-average particle diameter(D4) determined from the volume distribution and the number-based,number-average particle diameter (D1) determined from numberdistribution.

Charge Quantity

The toner for developing electrostatic latent images according to thepresent invention may preferably have a charge quantity (two-componentmethod) per unit weight, of from −10 to −80 μC/g, and more preferablyfrom −15 to −70 μC/g. This is preferable in order to improve transferefficiency in a transfer method making use of a transfer member to whicha voltage is kept applied.

A method of measuring the charge quantity quantity (two-componenttriboelectricity) by the two-component method used in the presentinvention is described below. In the measurement, a charge quantitymeasuring device shown in FIG. 7 is used. First, in a fixed environmentand using an iron powder EFV200/300 (available from Powder Teck Co.) asthe carrier, a mixture prepared by adding 0.5 g of the measuring-objecttoner to 9.5 g of the carrier is put in a bottle with a volume of 50 to100 mL, made of polyethylene, and is set on a shaker having a fixedshaking width, followed by shaking for a fixed time, setting shakingconditions at a shaking width of 100 mm and a shaking speed of 100to-and-fro times per minute. Then, 1.0 to 1.2 g of the resulting mixtureis put in a measuring container 42 made of a metal at the bottom ofwhich a screen 43 of 500 meshes is provided, and the container iscovered with a plate 44 made of a metal. The total weight of themeasuring container 42 at this time is weighed and is expressed as W1(g). Next, in a suction device (not shown; made of an insulatingmaterial at least at the part coming into contact with the measuringcontainer 42), air is sucked from a suction opening 47 and an air-flowcontrol valve 46 is operated to control the pressure indicated by avacuum indicator 45 to be 2,450 Pa (250 mmAq). In this state, suction iscarried out for 1 minute to remove the toner by suction. The potentialindicated by a potentiometer 49 at this time is expressed as V (volt).Herein, numeral 48 denotes a capacitor, whose capacitance is expressedas C (μF). The total weight of the measuring container after completionof the suction is also weighed and is expressed as W2 (g). The quantityof triboelectricity (μC/g) of the toner is calculated from thesemeasured values according to the following expression.

Calculational expression:Quantity of triboelectricity (μC/g)=C×V/(W1−W2)

Measurement of Molecular Weight of Binder Resin

In the present invention, the molecular weight of the binder resin ismeasured by GPC (gel permeation chromatography). As a specific methodfor measurement by GPC, a sample obtained by beforehand subjecting thetoner to extraction with a THF (tetrahydrofuran) solvent for 20 hours bymeans of a Soxhlet extractor is used for the measurement. As columnconstitution, A-801, A-802, A-803, A-804, A-805, A-806 and A-807,available from Showa Denko K. K., are connected, and the molecularweight distribution is measured using a calibration curve of standardpolystyrene resin.

In the present invention, it is also preferable to use as the binderresin a binder resin having a ratio of weight-average molecular weight(Mw) to number-average molecular weight (Mn), Mw/Mn, of from 2 to 100,as measured in the manner as described above.

Glass Transition Point of Toner

It is further preferable for the toner of the present invention to be soprepared as to have a glass transition point Tg of from 30° C. to 80°C., and more preferably from 50° C. to 70° C., in view of fixingperformance and storage stability. The glass transition point Tg in thiscase may be measured with, e.g., a differential scanning calorimeter ofa highly precise, inner-heat input compensation type, such as DSC-7,manufactured by Perkin-Elmer Corporation. It is measured according toASTM D3418-82. In the present invention, a measuring sample is onceheated to take a previous history and thereafter cooled rapidly. Then,the sample is again heated at a heating rate of 10° C./min. within thetemperature range of 0 to 200° C., where the DSC curve thus measured maybe used.

Image-forming Method and Apparatus

The toner for developing electrostatic latent images according to thepresent invention, constituted as described above, may particularlypreferably be applied to;

-   -   an image-forming method having at least a charging step of        applying a voltage to a charging member from its outside to        charge an electrostatic-latent-image-bearing member        electrostatically; a latent-image-forming step of forming an        electrostatic latent image on the        electrostatic-latent-image-bearing member thus charged; a        developing step of developing the electrostatic latent image by        the use of a toner to form a toner image on the        electrostatic-latent-image-bearing member; a transfer step of        transferring to a recording medium the toner image formed on the        electrostatic-latent-image-bearing member; and a heat fixing        step of fixing by heat the toner image held on the recording        medium; or    -   an image-forming method in which the transfer step comprises a        first transfer step of transferring to an intermediate transfer        member the toner image formed on the        electrostatic-latent-image-bearing member and a second transfer        step of transferring to a recording medium the toner image held        on the intermediate transfer member.

The apparatus used in this method may preferably have meanscorresponding to the respective steps, i.e., a charging means, anelectrostatic-latent-image-forming means, a developing means, a transfermeans and a heat fixing means.

EXAMPLES

The present invention is described below in greater detail by givingExamples and Comparative Examples. Also, “part(s)” in the following is“part(s) by weight” in all occurrences.

Example 1

In 20 L of M9 medium containing 0.5% of D-glucose and 0.1% of5-phenylvaleric acid (PVA), Pseudomonas cichorii strain YN2 (FERMBP-7375) was inoculated to effect spinner culture under aeration at 30°C., 80 revolutions/minute and an aeration rate of 2.5 L/minute. After 48hours, the bacterial body was collected by centrifugation, and thenagain suspended in 20 L of M9 medium containing 0.5% of D-glucose and0.1% of PVA and not containing any nitrogen source (NH₄Cl), furtherfollowed by spinner culture under aeration at 30° C., 80revolutions/minute and an aeration rate of 2.5 L/minute. After 48 hours,the bacterial body was collected by centrifugation. From the wetbacterial body thus collected, a 1 g portion was dispensed for its usein analysis and evaluation, and then washed once with cold methanol,followed by freeze-drying to obtain freeze-dried pellets.

In regard to the remaining wet bacterial body, it was suspended in 500mL of an aqueous solution of about 1.7% of sodium hypochlorite, whichwas then stirred at about 4° C. for 2 hours to extract a PHA. The PHAwas collected by centrifugation, followed by drying, so that the PHA wasobtained in an amount of 0.41 g per 1 L of the culture medium solution.This PHA was designated as PHAL, and was used as a binder resin.

Meanwhile, the freeze-dried pellets were suspended in 20 mL ofchloroform, which were then stirred at 60° C. for 20 hours to extract aPHA. The liquid extract obtained was filtered with a membrane filter of0.45 μm in pore diameter, and thereafter concentrated by means of arotary evaporator. The concentrated liquid was re-precipitated in coldmethanol, and further only the precipitate formed was collected,followed by vacuum drying to obtain a PHA.

The PHA thus obtained was compositionally analyzed in the following way:About 10 mg of the PHA was put into a 25 mL volume eggplant type flask,and dissolved in 2 mL of chloroform, followed by addition of 2 mL of amethanol solution containing 3% sulfuric acid to carry out reaction for3.5 hours under reflux at 100° C. After the reaction was completed, 10mL of deionized water was added to the reaction mixture, which was thenvigorously shaked for 10 minutes. Thereafter, of the two layersseparated, the lower layer chloroform layer was taken out, and thendehydrated with magnesium sulfate. Thereafter, this chloroform layer wasput to a gas chromatography mass spectrometer (GC-MS; apparatus:Shimadzu QP-5050; column: DB-WAX, J & W Co., 0.32 mm×30 m; EI method) tomake identification of the methyl-esterified products of PHA monomerunits. As the result, it was found that, as the PHA monomer units, 98%was held by a 3-hydroxy-5-phenylvaleric acid (3HPV) unit, and 2% a3-hydroxybutyric acid unit. Thus, a PHA having in a high percentage the3HPV monomer unit, the desired monomer unit derived from the PVA, wasobtained in a high yield.

The molecular weight of this PHA was also evaluated by gel permeationchromatography (GPC: Toso HLC-8220; column: Polymer Laboratory PLgelMIXED-C, 5 μm; solvent: chloroform; in terms of polystyrene). As theresult, its molecular weight was found to be Mn (number-averagemolecular weight)=85,200 and Mw (weight-average molecularweight)=213,000.

Example 2

A PHA containing a 3-hydroxy-5-(4-fluorophenyl)valeric acid (3HFPV)monomer unit was synthesized under entirely the same conditions as inExample 1 except that 5-(4-fluorophenyl)valeric acid (FPVA) was used inplace of the PVA. Thus, a PHA was obtained in an amount of 0.87 g per 1L of the culture medium solution. This PHA was designated as PHA2, andwas used as a binder resin.

The PHA obtained was analyzed and evaluated in the same manner as inExample 1 to find that, as the PHA monomer units, 96% was held by a3HFPV unit, and 4% a 3-hydroxybutyric acid unit. Thus, a PHA having in ahigh percentage the 3HFPV monomer unit, the desired monomer unit derivedfrom the PVA, was obtained in a high yield. Also, its molecular weightwas found to be Mn=71,500 and Mw=158,000.

Example 3

A PHA containing a 3-hydroxy-4-phenoxybutyric acid (3HPxB) monomer unitwas synthesized under entirely the same conditions as in Example 1except that 4-phenoxybutyric acid (PxBA) was used in place of the PVA.Thus, a PHA was obtained in an amount of 0.15 g per 1 L of the culturemedium solution. This PHA was designated as PHA3, and was used as abinder resin.

The PHA obtained was analyzed and evaluated in the same manner as inExample 1 to find that, as the PHA monomer units, 95% was held by a3HPxB unit, and 5% a 3-hydroxybutyric acid unit. Thus, a PHA having in ahigh percentage the 3HP×B monomer unit, the desired monomer unit derivedfrom the PxBA, was obtained in a high yield. Also, its molecular weightwas found to be Mn=71,500 and Mw=158,000.

Example 4

A PHA containing a 3-hydroxy-5-phenoxyvaleric acid (3HPxV) monomer unitwas synthesized under entirely the same conditions as in Example 1except that 5-phenoxyvaleric acid (PxVA) was used in place of the PVA.Thus, a PHA was obtained in an amount of 0.55 g per 1 L of the culturemedium solution. This PHA was designated as PHA4, and was used as abinder resin.

The PHA obtained was analyzed and evaluated in the same manner as inExample 1 to find that, as the PHA monomer units, 97% was held by a3HPxV unit, and 3% a 3-hydroxybutyric acid unit. Thus, a PHA having in ahigh percentage the 3HPxV monomer unit, the desired monomer unit derivedfrom the PxVA, was obtained in a high yield. Also, its molecular weightwas found to be Mn=69,500 and Mw=160,000.

Example 5

In 20 L of M9 medium containing 0.5% of D-glucose, Pseudomonas cichoriistrain YN2 was inoculated to effect shaking culture at 30° C. and 125strokes/minute for 72 hours. This cultured bacterial body was added to20 L of M9 medium containing 0.5% of D-glucose and 0.1% of FP×BA tosubsequently effect spinner culture under aeration at 30° C., 80revolutions/minute and an aeration rate of 2.5 L/minute. After 48 hours,the bacterial body was collected by centrifugation, and then againsuspended in 20 L of M9 medium containing 0.5% of D-glucose and 0.1% ofFPxBA (not containing any nitrogen source NH₄Cl), further followed byspinner culture under aeration at 30° C., 80 revolutions/minute and anaeration rate of 2.5 L/minute. After 48 hours, the bacterial body wascollected by centrifugation. From the wet bacterial body thus collected,a 1 g portion was dispensed for its use in analysis and evaluation, andthen washed once with cold methanol, followed by freeze-drying to obtainfreeze-dried pellets.

In regard to the remaining wet bacterial body, it was suspended in 500mL of an aqueous solution of about 1.7% of sodium hypochlorite, whichwas then stirred at about 4° C. for 2 hours to extract a PHA. The PHAwas collected by centrifugation, followed by drying, so that the PHA wasobtained in an amount of 0.24 g per 1 L of the culture medium solution.This PHA was designated as PHA5, and was used as a binder resin.

The PHA obtained was analyzed and evaluated in the same manner as inExample 1 to find that, as the PHA monomer units, 75% was held by a3-hydroxy-4-(4-fluorophenoxy)butyric acid (3HFPxB) unit, and 25% atleast one unit of 3-hydroxybutyric acid, 3-hydroxyhexanoic acid,3-hydroxyoctanoic acid, 3-hydroxydecanoic acid, 3-hydroxydodecanoic acidand 3-hydroxydodecenoic acid units. Thus, a PHA having in a highpercentage the 3HFPxB monomer unit, the desired monomer unit derivedfrom the FPxBA, was obtained in a high yield. Also, its molecular weightwas found to be Mn=45,200 and Mw=97,200.

This PHA was also analyzed by NMR spectroscopy under the followingmeasurement conditions to ascertain that the PHA obtained was chieflycomposed of the 3HFPxB unit.

Measuring Instrument

FT-NMR: Bruker DPX400.

Measurement Conditions

Resonance frequency: ¹H: 400 MHz.

-   -   ¹³C: 100 MHz

Measurement nuclide: ¹H, ¹³C

Solvent used: CDCl₃.

Reference: Capillary-encapsulated TMS/CDCl₃.

Measurement temperature: room temperature.

A measured ¹H-NMR spectrum chart is shown in FIG. 8. The results ofanalysis (identification) on main-peak signals of the NMR spectrum shownin FIG. 8 are shown in Table 1.

TABLE 1 ¹H-NMR Spectrum Measurement Results (see FIG. 8) Chemical Shift(ppm) Identification results 2.76 2H, CH₂ b1 3.95-4.06 2H, CH₂ d1 5.461H, CH c1 6.71-6.90 4H, —C₆H₄— f1, g1, i1, j1

Example 6

A PHA containing a 3-hydroxy-4-cyclohexylbutyric acid (3HCHB) monomerunit was synthesized under entirely the same conditions as in Example 1except that 4-cyclohexylbutyric acid (CHBA) was used in place of thePVA. Thus, a PHA was obtained in an amount of 0.79 g per 1 L of theculture medium solution. This PHA was designated as PHA6, and was usedas a binder resin.

The PHA obtained was analyzed and evaluated in the same manner as inExample 1 to find that, as the PHA monomer units, 98% was held by a3HCHB unit, and 2% a 3-hydroxybutyric acid unit. Thus, a PHA having in ahigh percentage the 3HCHB monomer unit, the desired monomer unit derivedfrom the CHBA, was obtained in a high yield. Also, its molecular weightwas found to be Mn=92,200 and Mw=218,000.

Example 7

A PHA containing a 3-hydroxy-4-(4-fluorocyclohexyl)butyric acid (3HFCHB)monomer unit was synthesized under entirely the same conditions as inExample 1 except that 4-(4-fluorocyclohexyl)butyric acid (FCHBA) wasused in place of the PVA. Thus, a PHA was obtained in an amount of 0.69g per 1 L of the culture medium solution. This PHA was designated asPHA7, and was used as a binder resin.

The PHA obtained was analyzed and evaluated in the same manner as inExample 1 to find that, as the PHA monomer units, 88% was held by a3HFCHB unit, and 12% a 3-hydroxybutyric acid unit. Thus, a PHA having ina high percentage the 3HFCHB monomer unit, the desired monomer unitderived from the FCHBA, was obtained in a high yield. Also, itsmolecular weight was found to be Mn=71,500 and Mw=158,000.

Example 8

A PHA containing a 3-hydroxy-5-benzoylvaleric acid (3HBzV) monomer unitwas synthesized under entirely the same conditions as in Example 1except that 5-benzoylvaleric acid (BzVA) was used in place of the PVA.Thus, a PHA was obtained in an amount of 0.52 g per 1 L of the culturemedium solution. This PHA was designated as PHA8, and was used as abinder resin.

The PHA obtained was analyzed and evaluated in the same manner as inExample 1 to find that, as the PHA monomer units, 82% was held by a3HBzV unit, and 18% a 3-hydroxybutyric acid unit. Thus, a PHA having ina high percentage the 3HBzV monomer unit, the desired monomer unitderived from the BzVA, was obtained in a high yield. Also, its molecularweight was found to be Mn=305,000 and Mw=1,150,000.

This PHA was also analyzed by NMR spectroscopy under the samemeasurement conditions as in Example 5 to ascertain that the PHAobtained was chiefly composed of the 3HBzV unit.

A ¹H-NMR spectrum and a ¹³C-NMR spectrum are shown in FIGS. 9 and 10,respectively, and its identification results, in Table 2.

TABLE 2 ¹H- and ¹³C-NMR spectra Identification Results ¹H ¹³C ChemicalChemical shift Integral shift Position (ppm) value Type (ppm) a — — —169.3 b 2.56 2 m 39.2 c 5.26 1 m 70.2 d 2.04 2 m 28.0 e 3   2 m 34.0 f —— — 198.6 g — — — 136.5 h, l 7.89 2 d 127.9 i, k 7.36 2 m 128.5 j 7.46 1t 133.0 d: doublet; t: triplet; m: multiplet

Example 9

A PHA containing a 3-hydroxy-5-(4-fluorobenzoyl)valeric acid (3HFBzV)monomer unit was synthesized under entirely the same conditions as inExample 1 except that 5-(4-fluorobenzoyl)valeric acid (FBzVA) was usedin place of the PVA. Thus, a PHA was obtained in an amount of 0.38 g per1 L of the culture medium solution. This PHA was designated as PHA9, andwas used as a binder resin.

The PHA obtained was analyzed and evaluated in the same manner as inExample 1 to find that, as the PHA monomer units, 75% was held by a3HFBzV unit, and 25% a 3-hydroxybutyric acid unit. Thus, a PHA having ina high percentage the 3HFBzV monomer unit, the desired monomer unitderived from the FBzVA, was obtained in a high yield. Also, itsmolecular weight was found to be Mn=275,000 and Mw=792,000.

This PHA was also analyzed by NMR spectroscopy under the samemeasurement conditions as in Example 5 to ascertain that the PHAobtained was chiefly composed of the 3HFBzV unit.

Example 10

A PHA containing a 3-hydroxy-5-(4-fluorophenyl)valeric acid (3HFPV)monomer unit and a 3-hydroxy-5-(4-fluorophenoxy)valeric acid (3HFPxV)monomer unit was synthesized under entirely the same conditions as inExample 1 except that 0.1% each of 5-(4-fluorophenyl)valeric acid (FPVA)and 5-(4-fluorophenoxy)valeric acid (FPxVA) were used in place of thePVA. Thus, a PHA was obtained in an amount of 0.85 g per 1 L of theculture medium solution. This PHA was designated as PHA10, and was usedas a binder resin.

The PHA obtained was analyzed and evaluated in the same manner as inExample 1 to find that, as the PHA monomer units, 90% was held by a3HFPV unit, 9% a 3HFPxV unit, and 1% at least one unit of3-hydroxybutyric acid, 3-hydroxyhexanoic acid, 3-hydroxyoctanoic acid,3-hydroxydecanoic acid, 3-hydroxydodecanoic acid and 3-hydroxydodecenoicacid units. Thus, a PHA having in a high percentage the 3HFPV and 3HFPxVmonomer units, the desired monomer units derived from the FPVA andFPxVA, respectively, was obtained in a high yield. Also, its molecularweight was found to be Mn=52,500 and Mw=127,000.

Example 11

A PHA containing a 3-hydroxy-7-phenoxyheptanoic acid (3HPxHp) monomerunit and a 3-hydroxy-5-phenoxyvaleric acid (3HPxV) monomer unit wassynthesized under entirely the same conditions as in Example 1 exceptthat 7-phenoxyheptanoic acid (PxHpA) was used in place of the PVA. Thus,a PHA was obtained in an amount of 0.92 g per 1 L of the culture mediumsolution. This PHA was designated as PHA11, and was used as a binderresin.

The PHA obtained was analyzed and evaluated in the same manner as inExample 1 to find that, as the PHA monomer units, 35% was held by a3HPxHp unit, 60% a 3HPxV unit, and 5% at least one unit of3-hydroxybutyric acid, 3-hydroxyhexanoic acid, 3-hydroxyoctanoic acid,3-hydroxydecanoic acid, 3-hydroxydodecanoic acid and 3-hydroxydodecenoicacid units. Thus, a PHA having in a high percentage the 3HPxHp and 3HPxVmonomer units, the desired monomer units derived from the PxHpA, wasobtained in a high yield. Also, its molecular weight was found to beMn=65,300 and Mw=132,000.

Example 12

150 g of polylactic acid (trade name: LACTY; available from ShimadzuCorporation; melt viscosity at 195° C.: 200,000 poises; weight-averagemolecular air weight: 200,000) and 50 g of the PHA of Example 1 (PHA1)were mixed. The mixture formed was put into an injection moldingmachine, and was melt-kneaded at temperature of 195 to 230° C. andmolded. The polymer blend thus obtained was designated as PHA12, and wasused as a binder resin.

Example 13

150 g of polylactic acid (trade name: LACTY; available from ShimadzuCorporation; melt viscosity at 195° C.: 200,000 poises; weight-averagemolecular weight: 200,000) and 50 g of the PHA of Example 4 (PHA4) weremixed. The mixture formed was put into an injection molding machine, andwas melt-kneaded at temperature of 195 to 230° C. and molded. Thepolymer blend thus obtained was designated as PHA13, and was used as abinder resin.

Example 14

150 g of polylactic acid (trade name: LACTY; available from ShimadzuCorporation; melt viscosity at 195° C.: 200,000 poises; weight-averagemolecular weight: 200,000) and 50 g of the PHA of Example 6 (PHA6) weremixed. The mixture formed was put into an injection molding machine, andwas melt-kneaded at temperature of 195 to 230° C. and molded. Thepolymer blend thus obtained was designated as PHA14, and was used as abinder resin.

Example 15

(by weight) PHA1 (Example 1) 100 parts Magenta pigment (C.I. Pigment Red114)  5 parts Charge control agent (NXVP434, available from Hoechst  2parts Japan Ltd.)

Materials formulated as shown above were melt-kneaded by means of atwin-screw extruder (L/D: 30). The kneaded product thus obtained wascooled, and thereafter, the cooled product was crushed using a hammermill, and then the crushed product was finely pulverized by means of ajet mill, followed by classification to obtain magenta colored particles(1) by pulverization. Particle size of the magenta colored particles (1)thus obtained was measured by the method described previously in thepresent specification, to find that it had a weight-average particlediameter of 15.3 μm and a fine-powder content of 1.2% by number.

In 100 parts by weight of the magenta colored particles (1), 1.5 partsby weight of hydrophobic fine silica powder having been treated withhexamethyldisilazane (BET specific surface area: 250 m²/g) was dry-mixedas a fluidity improver by means of a Henschel mixer to obtain a magentatoner 1 of this Example. Further, 7 parts by weight of the magenta toner1 thus obtained and 93 parts by weight of a resin-coated magneticferrite carrier (average particle diameter: 45 μm) were blended toprepare a two-component magenta developer 1 for magnetic-brushdevelopment.

Examples 16 to 28

Magenta toners 2 to 14 were obtained in the same manner as in Example 15except that 100 parts by weight of PHA2 to PHA14, respectively, wereused in place of PHA1. Characteristics of these toners were measured inthe same manner as in Example 15 to obtain the results shown in Table 3.Also, using these toners, two-component magenta developers 2 to 14,respectively, were prepared in the same manner as in Example 15.

Comparative Example 1

A magenta toner 15 of Comparative Example 1 was obtained in the samemanner as in Example 15 except that 100 parts by weight of styrene-butylacrylate copolymer resin (glass transition temperature: 70° C.) was usedin place of PHA1. Characteristics of this toner were measured in thesame manner as in Example 15 to obtain the results shown in Table 3.Also, using this toner, a two-component magenta developer 15 ofComparative Example 1 was prepared in the same manner as in Example 15.

Evaluation

On the two-component magenta developers 1 to 14 obtained in Examples 15to 28 and the two-component magenta developer 15 obtained in ComparativeExample 1, the charge quantity of each toner after agitation for 10seconds and 300 seconds was measured in each environment of normaltemperature and normal humidity (25° C., 60% RH) and high temperatureand high humidity (30° C., 80% RH) by the method described previouslyfor measuring charge quantity. Then, from the measured values oftwo-component blow-off charge quantity, the fractions to two decimalplaces were round off, and the charging performance was evaluatedaccording to the criteria shown below. The results are shown together inTable 3.

TABLE 3 Charging Performance of Magenta Toner 1 to 15 ChargingPerformance Particle Diameter Normal High Temperature DistributionTemperature and and Humidity Weight- Amount Humidity (Q/M) (Q/M) Averageof Fine 10- 300- 10- 300- Toner Particle Powder Second Second SecondSecond No.: Diameter (% by Agita- Agita- Agita- Agita- Example PHA No.Red (μm) number) tion tion tion tion 15 1 1 15.3 1.2 B A B A 16 2 2 9.13.5 A A A A 17 3 3 7.5 5.0 AA AA AA AA 18 4 4 7.1 5.2 AA AA AA AA 19 5 58.2 4.7 AA AA AA AA 20 6 6 9.9 2.3 A AA A A 21 7 7 8.0 4.2 AA AA AA AA22 8 8 7.2 4.1 AA AA AA AA 23 9 9 7.3 4.3 AA AA AA AA 24 10 10 7.6 4.0AA AA AA AA 25 11 11 7.5 5.7 AA AA AA AA 26 12 12 9.2 3.7 A AA A AA 2713 13 6.9 5.3 AA AA AA AA 28 14 14 8.3 4.1 A AA A AA Compar- — 15 7.04.9 AA AA AA AA ative Example  1(Charging performance)

-   AA: Very good (−20 μC/g or less).-   A: Good (−19.9 to −10.0 μC/g).-   B: Permissible for practical use (−9.9 to −5.0 μC/g).-   C: Impermissible for practical use (−4.9 μC/g or more)

Examples 29 to 42

Black toners 1 to 14 of Examples 29 to 42, respectively, were obtainedin the same manner as in Example 15 except that 100 parts by weight ofPHA1 to PHA14, respectively, were used and carbon black (DBP oilabsorption: 110 mL/100 g) was used in place of the magenta pigment.Characteristics of these toners were measured in the same manner as inExample 15 to obtain the results shown in Table 4. Also, using thesetoners, two-component black developers 1 to 14, respectively, wereprepared in the same manner as in Example 15.

Comparative Example 2

A black toner 15 of Comparative Example 2 was obtained in the samemanner as in Example 15 except that 100 parts by weight of styrene-butylacrylate copolymer resin (glass transition temperature: 70° C.) was usedin place of PHA1 and carbon black (DBP oil absorption: 110 mL/100 g) wasused in place of the magenta pigment. Characteristics of these tonerswere measured in the same manner as in Example 15 to obtain the resultsshown in Table 4. Also, using this toner, a two-component blackdeveloper 15 was prepared in the same manner as in Example 15.

Evaluation

On the two-component black developers 1 to 14 obtained in Examples 29 to42 and the two-component black developer 15 obtained in ComparativeExample 2, the charge quantity of each toner after agitation for 10seconds and 300 seconds was measured in each environment of normaltemperature and normal humidity (25° C., 60% RH) and high temperatureand high humidity (30° C., 80% RH) by the method described previouslyfor measuring charge quantity. Then, from the measured values oftwo-component blow-off charge quantity, the fractions to two decimalplaces were round off, and the charging performance was evaluatedaccording to the criteria shown below. The results are shown together inTable 4.

TABLE 4 Charging Performance of Black Toners 1 to 15 ChargingPerformance Particle Diameter Normal High Temperature DistributionTemperature and and Humidity Weight- Amount Humidity (Q/M) (Q/M) Averageof Fine 10- 300- 10- 300- Toner Particle Powder Second Second SecondSecond No.: Diameter (% by Agita- Agita- Agita- Agita- Example PHA No.Black (μm) number) tion tion tion tion 29 1 1 14.6 1.8 B A B B 30 2 28.8 3.0 A A B A 31 3 3 7.3 5.4 AA AA AA AA 32 4 4 7.0 5.5 AA AA AA AA 335 5 7.9 4.5 AA AA AA AA 34 6 6 9.2 2.7 A A B A 35 7 7 7.7 4.0 AA AA AAAA 36 8 8 7.3 4.4 AA AA AA AA 37 9 9 7.3 4.5 AA AA AA AA 38 10 10 7.34.8 AA AA AA AA 39 11 11 7.2 5.4 AA AA AA AA 40 12 12 9.8 3.0 A A B A 4113 13 7.2 5.0 AA AA AA AA 42 14 14 8.0 4.9 A AA A A Compar- — 15 7.1 5.1AA AA AA AA ative Example 2(Charging performance)

-   AA: Very good (−20 μC/g or less).-   A: Good (−19.9 to −10.0 μC/g).-   B: Permissible for practical use (−9.9 to −5.0 μC/g).-   C: Impermissible for practical use (−4.9 μC/g or more).

Example 43

Deinking Test

(The removal of toner from paper is herein compared to “deinking”.)

Using each of the black toners 1 to 15 obtained in Examples 29 to 42 andComparative Example 2, a testing image of 6% in black-and-white ratio(image area percentage) was formed on the surface of paper of 75 g/m² inbasis weight to make testing paper. Using this testing paper, hand-madesheets for evaluation were prepared under the following conditions.

Defiberization: An aqueous dispersion composed of the following isstirred in a beaker at 50° C. for 20 minutes to defiberize the testingpaper.

Testing paper 5.0% NaOH 0.7% Sodium silicate 3.0% H₂O₂ 1.0%Deinking agent (LIPTOL S 2800, trade name; available from LionCorporation 0.2%

Dilution, dehydration and kneader treatment: The above aqueousdispersion is diluted with water to a 5% dispersion, which is thensubjected to centrifugal dehydration. Pulp, sodium silicate and so forthare further so added that the pulp is in a content of 20%, the sodiumsilicate 3.0% and NaOH 0.5%, to carry out defiberization by means of akneader.

Aging: The kneader-defiberized product is aged at 50° C. for 2 hours.

Flotation: Water is added to the aged product to prepare a dispersionwith a pulp concentration of 1%. Into the dispersion, minute air bubblesare released for 7 minutes to make the air bubbles adsorb the toner inthe dispersion to allow the latter to come up to the surface, where thetoner and the water are separated.

Washing: 2.4 g of the deinked pulp is washed twice with 1 liter of waterfor each.

Preparation of testing hand-made sheets: Hand-made sheets (basis weight:100 g/m²) are prepared by means of a TAPPI standard sheet machine.

Evaluation of deinkability: The number of toner particles present in 9cm² of each hand-made sheet is both visually and microscopicallyobserved to make evaluation individually for two groups of size, 100 μmor more (the size in which the particles are visible to the naked eye)and 60 μm to less than 100 μm.

The results of the above test are shown in Table 5. In Table 5,numerical values indicate the number of remaining toner particles.

TABLE 5 Deinkability Test Results Number of particles 60 to <100 μm 100μm or more Total Example: 29 10 12 22 30 13 14 27 31  9 14 23 32 13 1124 33 17 18 35 34  8 13 21 35 18 17 35 36 15 12 27 37 17 15 32 38 16 1531 39 11 13 24 40 17 19 36 41 19 20 39 42 15 15 30 Comparative Example: 2 43 38 81

Example 44

Biodegradability Test

The red (magenta) toners 1 to 14, the black toners 1 to 14, thecomparative red toner 15 and the comparative black toner 15 weremelt-shaped into films of about 50 μm in thickness, which were then leftin soil for 6 months. As the result, the films of the red toners 1 to 11and black toners 1 to 11 had completely disappeared in shape, and thefilms of the red toners 12 to 14 and black toners 12 to 14 haddisappeared in its greater part. On the other hand, the comparative redtoner 15 and the comparative black toner 15 stood remained in shape asthey were.

Examples 45 to 72 & Comparative Examples 3 and 4

An image-forming apparatus used in image-forming processes in Examples45 to 72 and Comparative Examples 3 and 4 is described first. FIG. 1 isa schematic sectional illustration of an image-forming apparatus forcarrying out image-forming processes in Examples 45 to 72 andComparative Examples 3 and 4.

As shown in FIG. 1, a photosensitive drum 1 comprises a substrate 1 band provided thereon a photosensitive layer 1 a having an organicphoto-semiconductor, and is so constructed as to be rotated in thedirection of an arrow. By means of a charging roller 2 which is acharging member facing the photosensitive drum 1 and rotated in contactwith the drum, the surface of the photosensitive drum iselectrostatically charged to have a surface potential of about −600 V.As shown in FIG. 1, the charging roller 2 is constituted of a mandrel 2b and a conductive elastic layer 2 a covered thereon.

Next, the photosensitive drum 1 whose surface is kept charged is exposedto light 3, where an electrostatic latent image having an exposed-areapotential of −100 V and a dark-area potential of −600 V is formed on thephotosensitive drum by on-off control in accordance with digital imageinformation through a polygon mirror. Subsequently, the electrostaticlatent image formed on this photosensitive drum 1 is rendered visible byreversal development by means of a plurality of developing assembliesfor four colors, 4-1, 4-2, 4-3 and 4-4, so that four-color toner imagesare formed on the photosensitive drum 1. Here, as a magenta or blackdeveloper, the two-component developers obtained in Examples 15 to 42and Comparative Examples 1 and 2 are each used, and toner images areformed using each of the magenta toners or black toners. FIG. 2 is anenlarged sectional view of the main part of each developing assembly 4for two-component developer, used here. Next, the toner images formed onthe photosensitive drum 1 are transferred to an intermediate transfermember 5 rotated in contact with the photosensitive drum 1. As theresult, four color, color-superimposed visible images are formed on theintermediate transfer member 5. Transfer residual toner having remainedon the photosensitive drum 1 without being transferred is collected in aresidual toner container 9 by means of a cleaning member 8.

The intermediate transfer member 5 is, as shown in FIG. 1, constitutedof a mandrel 5 b as a support and an elastic layer 5 a layered thereon.In the present Examples, an intermediate transfer member 5 was usedwhich had a pipe-like mandrel 5 b and an elastic layer 5 a providedthereon by coating, formed of nitrile-butadiene rubber (NBR) in whichcarbon black as a conductivity-providing agent had been well dispersed.The elastic layer 5 a thus formed had a hardness measured according toJIS K-6301, of 30 degrees and a volume resistivity of 10⁹ Ω·cm. Transferelectric current necessary for the transfer from the photosensitive drum1 to the intermediate transfer member 5 was about 5 μA, which wasobtained by applying a voltage of +500 V to the mandrel 5 b from a powersource.

The four color, color-superimposed visible images formed on theintermediate transfer member 5 are transferred to a transfer medium suchas paper by means of a transfer roller 7, and thereafter fixed by meansof a heat-fixing assembly H to come into permanent form. The transferroller 7 has an elastic layer 7 a formed by coating on a mandrel 7 b of10 mm in diameter a foamable material of an ethylene-propylene-dieneterpolymer (EPDM) in which carbon black as a conductivity-providingagent has been well dispersed. Here, as the elastic layer 7 a, oneshowing a volume resistivity of 10⁶ Ω·cm and a hardness measuredaccording to JIS K-6301, of 35 degrees was used. A voltage was appliedto the transfer roller 7 to flow a transfer current of 15 μA.

In the apparatus shown in FIG. 1, as the heat fixing assembly H, afixing assembly of a hot-roll type having no function of oil applicationas shown in FIGS. 5 and 6 is used. Here, as both the upper roller andthe lower roller, those having surface layers formed of a fluorine resinwere used. The roller was in a diameter of 60 mm. The fixing temperaturewas set at 160° C., and the nip width at 7 mm. Also, the transferresidual toner on the photosensitive drum 1, having been collected bycleaning, was transported to the developing assemblies by means of areuse mechanism and was again used.

Evaluation

Under the above conditions, a printing test was made in environments ofnormal temperature and normal humidity (25° C., 60% RH) and hightemperature and high humidity (30° C., 80% RH) at a printing speed of 8sheets (A4-size)/minute in a monochromatic intermittent mode (i.e., amode in which the developing assembly was made to pause for 10 secondsevery time the images were printed on one sheet so that thedeterioration of the toner was accelerated by preliminary operation ofthe developing assembly when again driven) while successively supplyingeach of the two-component developers prepared using the toners ofExamples 15 to 42 and the two-component developers prepared using thetoners of Comparative Examples 1 and 2. Then, evaluation on printedimages thus obtained was made in respect of the items shown below. Theresults obtained are shown in Table 6.

Printed-Image Evaluation

1. Image density:

Evaluated on how image density was maintained on images at the time offinish of printing with respect to images at the initial stage whenimages were printed on a prescribed number of sheets of usual plainpaper (75 g/m²) for copying machines. Here, the image density wasmeasured with Macbeth Reflection Densitometer (manufactured by MacbethCo.), as relative density with respect to an image printed on a whiteground area with a density of 0.00 of an original. The measurements wereused in evaluation.

-   AA: Excellent (the image density at the time of finish is 1.40 or    more).-   A: Good (the image density at the time of finish is from 1.35 to    less than 1.40).-   C: Passable (the image density at the time of finish is from 1.00 to    less than 1.35).-   D: Failure (the image density at the time of finish is less than    1.00).

2. Image fog:

Evaluated on how solid white images stood at the time of finish ofprinting when images were printed on a prescribed number of sheets ofusual plain paper (75 g/m²) for copying machines. Stated specifically,it was evaluated in the following way: The worst value ofwhite-background reflection density after printing, measured with areflection densitometer (REFLECTOMETER MODEL TC-6DS, manufactured byTokyo Denshoku Co., Ltd.), was regarded as Ds, and an average value ofreflection densities of paper before printing, as Dr. From these values,the value of Ds−Dr was found and this was regarded as the amount of fogto make evaluation according to the following criteria.

-   AA: Very good (the amount of fog is from 0% to less than 1.5%).-   A: Good (the amount of fog is from 1.5% to less than 3.0%).-   B: Permissible for practical use (the amount of fog is from 3.0% to    less than 5.0%).-   C: Impermissible for practical use (the amount of fog is 5.0% or    more).

3. Transfer performance:

Solid black images were printed on a prescribed number of sheets ofusual plain paper (75 g/m²) for copying machines, and the level of imageblank areas in images at the time of finish of printing was observedvisually to make evaluation according to the following criteria.

-   AA: Very good (the image blank areas little occur).-   A: Good (occur only slightly).-   B: Permissible for practical use.-   C: Impermissible for practical use.

Evaluation was also visually made on whether or not, when images werereproduced on 5,000 sheets in Examples 45 to 72 and Comparative Examples3 and 4, any scratches of the surfaces of the photosensitive drum andintermediate transfer member or any sticking of remaining toner occurredand how these affected the printed images (i.e., matching withimage-forming apparatus). As the result, the toner was seen to haveslightly stuck to the photosensitive-drum surface in all systems inwhich the two-component developers of Examples 45 and 59 were used.

In the systems in which two-component developers other than theforegoing were used, any scratches of the surfaces of the photosensitivedrum and intermediate transfer member or any sticking of remaining tonerwere not seen to have occurred at all, showing very good matching withthe image-forming apparatus.

TABLE 6 Printed-Image Evaluation Results Normal Temperature HighTemperature Two- and Humidity and Humidity component Image ImageTransfer Image Image Transfer Example Developer Density Fog PerformanceDensity Fog Performance 45 Red 1 A B B A B B 46 Red 2 A A A A B B 47 Red3 AA AA AA AA AA AA 48 Red 4 AA AA AA AA AA AA 49 Red 5 AA AA AA AA AAAA 50 Red 6 AA AA A A A B 51 Red 7 AA AA AA AA AA AA 52 Red 8 AA AA AAAA AA AA 53 Red 9 AA AA AA AA AA AA 54 Red 10 AA AA AA AA AA AA 55 Red11 AA AA AA AA AA AA 56 Red 12 A A A A B B 57 Red 13 AA AA AA AA AA AA58 Red 14 A A A A B B 59 Black 1 A B B A B B 60 Black 2 A A A A B B 61Black 3 AA AA AA AA AA AA 62 Black 4 AA AA AA AA AA AA 63 Black 5 AA AAAA AA AA AA 64 Black 6 AA AA A A B B 65 Black 7 AA AA AA AA AA AA 66Black 8 AA AA AA AA AA AA 67 Black 9 AA AA AA AA AA AA 68 Black 10 AA AAAA AA AA AA 69 Black 11 AA AA AA AA AA AA 70 Black 12 A A A A B B 71Black 13 AA AA AA AA AA AA 72 Black 14 A A A A B B Compar- Red 15 AA AAAA AA AA AA ative Example 3 4 Black 15 AA AA AA AA AA AA

Examples 73 to 84 & Comparative Examples 5 and 6.

In carrying out image-forming processes in Examples 73 to 84 andComparative Examples 5 and 6, the toners obtained in Examples 31 to 42and Comparative Examples 1 and 2 were used as developers, respectively.As a means for forming images, an image-forming apparatus was used inwhich a reuse mechanism was attached to a commercially available laserbeam printer LBP-EX (manufactured by CANON INC.) to remodel the printer,which was again set up and used. More specifically, the image-formingapparatus shown in FIG. 3 is fitted with a system in which theuntransferred toner having remained on the surface of a photosensitivedrum 20 after transfer is scraped off with an elastic blade 22 of acleaner 21, coming into touch with the photosensitive drum 20, and issent into the cleaner 21, where the toner thus collected is transportedthrough a cleaner screw 23 by means of a feed pipe 24 provided with atransport screw, and, through a hopper 25, returned to a developingassembly 26, and the toner thus collected is again used for development.

In the image-forming apparatus shown in FIG. 3, the surface of thephotosensitive drum 20 is electrostatically charged by means of aprimary charging roller 27. In the primary charging roller 27, used is arubber roller (diameter: 12 mm; contact pressure: 50 g/cm) in whichconductive carbon has been dispersed, and covered with a nylon resin.Here, on the electrostatic latent image bearing member (photosensitivedrum 20), an electrostatic latent image with a dark-area potential VD of−700 V and a light-area potential VL of −200 V were formed by laserexposure (600 dpi, not shown). As a toner carrying member, a developingsleeve 28 whose surface was coated with a resin having carbon blackdispersed therein and had a surface roughness Ra of 1.1 was used.

In FIG. 4, shown is an enlarged sectional view of the main part of adeveloping assembly for one-component developer, used in Examples 73 to84 and Comparative Examples 5 and 6. As conditions for developingelectrostatic latent images, the surface movement speed of thedeveloping sleeve 28 was so set as to be 1.1 times the movement speed ofthe photosensitive drum 20 surface, and also the gap α (S−D distance)between the photosensitive drum 20 and the developing sleeve 28 was setto be 270 μm. As a toner layer thickness regulation member, a blade 29made of urethane rubber was used in contact with the developing sleeve.Also, the temperature of the heat-fixing assembly for fixing tonerimages was set at 160° C. As the fixing assembly, a fixing assembly (afixing film type) shown in FIGS. 5 and 6 was used.

Under the above conditions, a 30,000-sheet printing test was made in anenvironment of normal temperature and normal humidity (25° C., 60% RH)at a printing speed of 8 sheets (A4-size)/minute in a continuous mode(i.e., a mode in which the developing assembly was not made to pause sothat the consumption of the toner was accelerated) while successivelysupplying the toner. On the printed images thus formed, their imagedensity was measured and how the image density changed during runningwas examined to make evaluation according to the criteria shown below.Also, images on the 10,000th sheet were observed and evaluation on imagefog was made according to the criteria shown below. At the same time,how the units constituting the image-forming apparatus stood after therunning test was also observed to make evaluation also on the matchingof the respective toners with the units.

The results of the foregoing are shown together in Table 7.

Change in image density during running:

Evaluated on how image density was maintained on images at the time offinish of printing with respect to images at the initial stage whenimages were printed on a prescribed number of sheets of usual plainpaper (75 g/m²) for copying machines. Here, the image density wasmeasured with Macbeth Reflection Densitometer (manufactured by MacbethCo.), as relative density with respect to an image printed on a whiteground area with a density of 0.00 of an original. The measurements wereused in evaluation.

-   AA: Excellent (the image density at the time of finish is 1.40 or    more).-   A: Good (the image density at the time of finish is from 1.35 to    less than 1.40).-   C: Passable (the image density at the time of finish is from 1.00 to    less than 1.35).-   D: Failure (the image density at the time of finish is less than    1.00).

Image fog:

Evaluated on how solid white images stood at the time of finish ofprinting when images were printed on a prescribed number of sheets ofusual plain paper (75 g/m²) for copying machines. Stated specifically,it was evaluated in the following way: The worst value ofwhite-background reflection density after printing, measured with areflection densitometer (REFLECTOMETER MODEL TC-6DS, manufactured byTokyo Denshoku Co., Ltd.), was regarded as Ds, and an average value ofreflection densities of paper before printing, as Dr. From these values,the value of Ds−Dr was found and this was regarded as the amount of fogto make evaluation according to the following criteria.

-   AA: Very good (the amount of fog is from 0% to less than 1.5%).-   A: Good (the amount of fog is from 1.5% to less than 3.0%).-   B: Permissible for practical use (the amount of fog is from 3.0% to    less than 5.0%).-   C: Impermissible for practical use (the amount of fog is 5.0% or    more).

Evaluation on Matching with Image Forming Apparatus:

1. Matching with developing sleeve:

After the printing test was finished, evaluation was visually made byexamining any sticking of the toner remaining on the developing-sleevesurface and how it affected the printed images.

-   AA: Very good (no sticking occurs).-   A: Good (sticking little occurs).-   B: Permissible for practical use (sticking is a little seen, but    less affects images).-   C: Impermissible for practical use (sticking is greatly seen, and    uneven images occur).

2. Matching with photosensitive drum:

Evaluation was visually made by examining any scratches of thephotosensitive-drum surface and any sticking of the toner remainingthereon, and how they affected the printed images

-   AA: Very good (none of them occurs).-   A: Good (scratches are seen to slightly occur, but do not affect    images).-   B: Permissible for practical use (sticking and scratches are seen,    but less affect images).-   C: Impermissible for practical use (sticking is greatly seen, and    faulty images occur as vertical lines).

3. Matching with fixing assembly:

How the fixing-film surface stood was observed, and the results on itssurface properties and any sticking of the toner remaining on itssurface were overall averaged to evaluate its durability.

(1) Surface properties

After the printing test was finished, evaluation was made by visuallyobserving any scratches or abrasion of the fixing-film surface.

-   AA: Very good (none of them occurs).-   A: Good (they little occur).-   B: Permissible for practical use.-   C: Impermissible for practical use.

(2) Sticking of remaining toner:

After the printing test was finished, evaluation was made by visuallyobserving any sticking of the toner remaining on the fixing-filmsurface.

-   AA: Very good (no sticking occurs).-   A: Good (sticking little occurs).-   B: Permissible for practical use.-   C: Impermissible for practical use.

TABLE 7 Printed-Image Evaluation Results and Matching with Image-FormingApparatus Evaluation of Printed Image Evaluation of Matching withconstituent units Change in Image Density during Photo- Fixing Assemblyrunning Image Fog sensi- Surface Initial 1000th 10,000th 30,000th10,000th Develop- tive Proper- Sticking of Example Toner Print PrintPrint Print Print ing Sleeve Drum ties Toner 73 Black 3 AA AA AA AA AAAA AA AA AA 74 Black 4 AA AA AA AA AA AA AA AA AA 75 Black 5 AA AA AA AAAA AA AA AA AA 76 Black 6 AA A A B A A AA AA A 77 Black 7 AA AA AA AA AAAA AA AA AA 78 Black 8 AA AA AA AA AA AA AA AA AA 79 Black 9 AA AA AA AAAA AA AA AA AA 80 Black 10 AA AA AA AA AA AA AA AA AA 81 Black 11 AA AAAA AA AA AA AA AA AA 82 Black 12 A A B B B A AA A A 83 Black 13 AA AA AAAA AA AA AA AA AA 84 Black 14 A A B B B A AA AA A Compar- Red 15 AA AAAA AA AA AA AA AA AA ative Example  5  6 Black 15 AA AA AA AA AA AA AAAA AA

Examples 85 to 87

Successively supplying the black toners 4, 8 and 9 of Examples 32, 36and 37, respectively, printing tests were made in a continuous mode(i.e., a mode in which the developing assembly was not made to pause sothat the consumption of the toner was accelerated), in the same manneras in Example 84 except that the toner reuse mechanism of the FIG. 3image-forming apparatus was detached and the printing speed was changedto 16 sheets (A4-size)/minute. The printed images obtained and thematching with the image-forming apparatus used were evaluated on thesame items as those in Examples 73 to 84 and Comparative Examples 5 and6. As the result, good results were obtained on all the items.

1. In a binder resin forming a resin powdery product, the improvementwherein the binder resin comprises a polyhydroxyalkanoate having amonomer unit composition represented by the following Formula (1):AmB(1−m)  (1) wherein A is at least one selected from monomer unitsrepresented by the following Formula (2), B is at least one selectedfrom monomer units represented by the following Formulas (3) and (4),and m is 0.01 or more and 1 or less:

wherein n is 0 to 10, k is 3 or 5, and R is any group selected fromgroups represented by the following Formulas (5) to (8):

wherein; in Formula (5), R1 is selected from a hydrogen atom (H) and afluorine atom (F), and q is selected from integers of 1 to 8; in Formula(6), R2 is selected from a hydrogen atom (H) and a fluorine atom (F),and r is selected from integers of 1 to 8; in Formula (7), R3 isselected from a hydrogen atom (H) and a fluorine atom (F), and s isselected from integers of 1 to 8; and in Formula (8), R4 is selectedfrom a hydrogen atom (H) and a fluorine atom (F), and t is selected fromintegers of 1 to
 8. 2. The binder resin according to claim 1, whichfurther comprises at least one of polycaprolactone and polylactic acid.3. The binder resin according to claim 1, which has a number-averagemolecular weight from 2,000 to 300,000.
 4. The binder resin according toclaim 1, which has a glass transition point from 30° C. to 80° C., and asoftening point from 60° C. to 170° C.
 5. The binder resin according toclaim 1, wherein the resin powdery product is a toner for developingelectrostatic latent images.
 6. In a toner for developing electrostaticlatent images, the toner comprising a pigment and a binder resin whichforms a resin powdery product, the improvement wherein the binder resincomprises a polyhydroxyalkanoate having a monomer unit compositionrepresented by the following Formula (1):AmB(1−m)  (1) wherein A is at least one selected from monomer unitsrepresented by the following Formula (2), B is at least one selectedfrom monomer units represented by the following Formulas (3) and (4),and m is 0.01 or more and 1 or less:

wherein n is 0 to 10, k is 3 or 5, and R is any group selected fromgroups represented by the following Formulas (5) to (8):

wherein; in Formula (5), R1 is selected from a hydrogen atom (H) and afluorine atom (F), and q is selected from integers of 1 to 8; in Formula(6), R2 is selected from a hydrogen atom (H) and a fluorine atom (F),and r is selected from integers of 1 to 8; in Formula (7), R3 isselected from a hydrogen atom (H) and a fluorine atom (F), and s isselected from integers of 1 to 8; and in Formula (8), R4 is selectedfrom a hydrogen atom (H) and a fluorine atom (F), and t is selected fromintegers of 1 to
 8. 7. An image-forming method comprising: a chargingstep of applying a voltage to a charging member from its outside tocharge an electrostatic-latent-image-bearing member electrostatically; alatent-image-forming step of forming an electrostatic latent image onthe electrostatic-latent-image-bearing member thus charged; a developingstep of developing the electrostatic latent image by the use of a tonerfor developing electrostatic latent images, to form a toner image on theelectrostatic-latent-image-bearing member; a transfer step oftransferring to a recording medium the toner image formed on theelectrostatic-latent-image-bearing member; and a fixing step of fixingby heat the toner image held on the recording medium; wherein the tonerfor developing electrostatic latent images according to claim 6 is used.8. An image-forming method according to claim 7, wherein the transferstep further comprises: a first transfer step of transferring to anintermediate transfer member the toner image formed on theelectrostatic-latent-image-bearing member; and a second transfer step oftransferring to a recording medium the toner image held on theintermediate transfer member.
 9. An image-forming apparatus comprising:a charging means for applying a voltage to a charging member from itsoutside to charge an electrostatic-latent-image-bearing memberelectrostatically; a latent-image-forming means for forming anelectrostatic latent image on the electrostatic-latent-image-bearingmember thus charged; a developing means for developing the electrostaticlatent image by the use of a toner for developing electrostatic latentimages, to form a toner image on the electrostatic-latent-image-bearingmember; a transfer means for transferring to a recording medium thetoner image formed on the electrostatic-latent-image-bearing member; anda fixing means for fixing by heat the toner image held on the recordingmedium; wherein the toner for developing electrostatic latent imagesaccording to claim 6 is used.
 10. An image-forming apparatus accordingto claim 9, wherein the transfer means further comprises: a firsttransfer means for transferring to an intermediate transfer member thetoner image formed on the electrostatic-latent-image-bearing member; anda second transfer means for transferring to a recording medium the tonerimage held on the intermediate transfer member.